doc: remove "nvim-" qualfier from tags

It is almost never necessary to qualify documentation as "Nvim
specific".

The main exception to this is vim_diff.txt.

runtime/doc/api.txt

@@ -1,31 +1,32 @@
-*api.txt*    For Nvim.							 {Nvim}
+*api.txt*		 						{Nvim}
 
 
 		 NVIM REFERENCE MANUAL    by Thiago de Arruda
 
-The C API of Nvim						     *nvim-api*
 
-1. Introduction			|nvim-api-intro|
-2. API Types			|nvim-api-types|
-3. API metadata			|nvim-api-metadata|
-4. Buffer highlighting		|nvim-api-highlights|
+C API for Nvim							   *API* *api*
+
+1. Introduction			|api-intro|
+2. API Types			|api-types|
+3. API metadata			|api-metadata|
+4. Buffer highlighting		|api-highlights|
 
 ==============================================================================
-1. Introduction			*nvim-api-intro*
+1. Introduction							   *api-intro*
 
-Nvim defines a C API as the primary way for external code to interact with
-the Nvim core. In the present version of Nvim the API is primarily used by
-external processes to interact with Nvim using the msgpack-rpc protocol, see
-|msgpack-rpc|. The API will also be used from vimscript to access new Nvim core
-features, but this is not implemented yet. Later on, Nvim might be embeddable
-in C applications as libnvim, and the application will then control the
-embedded instance by calling the C API directly.
+Nvim exposes a public API for external code to interact with the Nvim core. In
+the present version of Nvim the API is primarily used by external processes to
+interact with Nvim using the msgpack-rpc protocol, see |msgpack-rpc|. The API
+will also be used from vimscript to access new Nvim core features, but this is
+not implemented yet. Later on, Nvim might be embeddable in C applications as
+libnvim, and the application will then control the embedded instance by
+calling the C API directly.
 
 ==============================================================================
-2. API Types						       *nvim-api-types*
+2. API Types							   *api-types*
 
 Nvim's C API uses custom types for all functions. Some are just typedefs
-around C99 standard types, and some are Nvim defined data structures.
+around C99 standard types, and some are Nvim-defined data structures.
 
 Boolean				  -> bool
 Integer (signed 64-bit integer)	  -> int64_t
@@ -46,7 +47,7 @@ Window				  -> enum value kObjectTypeWindow
 Tabpage				  -> enum value kObjectTypeTabpage
 
 ==============================================================================
-3. API metadata						    *nvim-api-metadata*
+3. API metadata							 *api-metadata*
 
 Nvim exposes metadata about the API as a Dictionary with the following keys:
 
@@ -58,7 +59,7 @@ This metadata is mostly useful for external programs accessing the API via
 RPC, see |rpc-api|.
 
 ==============================================================================
-4. Buffer highlighting					  *nvim-api-highlights*
+4. Buffer highlighting					       *api-highlights*
 
 Nvim allows plugins to add position-based highlights to buffers. This is
 similar to |matchaddpos()| but with some key differences. The added highlights

runtime/doc/develop.txt

@@ -9,12 +9,12 @@ Development of Nvim.					*development*
 1. Design goals		|design-goals|
 2. Design decisions	|design-decisions|
 
-See src/nvim/README.md for a high-level overview of the source code:
-    https://github.com/neovim/neovim/blob/master/src/nvim/README.md
-
 Nvim is open source software.  Everybody is encouraged to contribute.
     https://github.com/neovim/neovim/blob/master/CONTRIBUTING.md
 
+See src/nvim/README.md for a high-level overview of the source code:
+    https://github.com/neovim/neovim/blob/master/src/nvim/README.md
+
 ==============================================================================
 1. Design goals						*design-goals*
 
@@ -72,6 +72,9 @@ NVIM IS... WELL DOCUMENTED				*design-documented*
   recommended.
 - Don't make the text unnecessarily long.  Less documentation means that an
   item is easier to find.
+- Do not prefix doc-tags with "nvim-". Use |vim_diff.txt| to document
+  differences from Vim. The {Nvim} annotation is also available
+  to mark a specific feature. No other distinction is necessary.
 
 
 NVIM IS... HIGH SPEED AND SMALL IN SIZE			*design-speed-size*
@@ -85,8 +88,6 @@ fast.
   possible.  Useful commands may take longer.
 - Don't forget that some people use Vim over a slow connection.  Minimize the
   communication overhead.
-- Items that add considerably to the size and are not used by many people
-  should be a feature that can be disabled.
 - Vim is a component among other components.  Don't turn it into a massive
   application, but have it work well together with other programs.
 
@@ -113,25 +114,14 @@ be used to adjust Vim to the desire of the user and its environment.
 
 NVIM IS... NOT						*design-not*
 
-Nvim is not an operating system—instead it should be composed with other tools
-or hosted as a component. Marvim once said: "Unlike Emacs, Nvim does not
+Nvim is not an operating system; instead it should be composed with other
+tools or hosted as a component. Marvim once said: "Unlike Emacs, Nvim does not
 include the kitchen sink... but you can use it for plumbing."
 
 
 ==============================================================================
 2. Design decisions					*design-decisions*
 
-Folding
-
-Several forms of folding should be possible for the same buffer.  For example,
-have one window that shows the text with function bodies folded, another
-window that shows a function body.
-
-Folding is a way to display the text.  It should not change the text itself.
-Therefore the folding has been implemented as a filter between the text stored
-in a buffer (buffer lines) and the text displayed in a window (logical lines).
-
-
 Naming the window
 
 The word "window" is commonly used for several things: A window on the screen,
@@ -147,6 +137,8 @@ window		View on a buffer.  There can be several windows in Vim,
 		together with the command line, menubar, toolbar, etc. they
 		fit in the shell.
 
-
+RPC API
+API client
+remote plugin
 
  vim:tw=78:ts=8:ft=help:norl:

runtime/doc/msgpack_rpc.txt

@@ -35,10 +35,10 @@ The RPC API is like a more powerful version of Vim's `clientserver` feature.
 ==============================================================================
  2. API mapping							    *rpc-api*
 
-The Nvim C API, see |nvim-api|, is automatically exposed to the RPC API by the
-build system, which parses headers at src/nvim/api/*. A dispatch function is
-generated which matches RPC API method names with public API functions,
-converting/validating arguments and return values back to msgpack.
+The Nvim C |API| is automatically exposed to the RPC API by the build system,
+which parses headers at src/nvim/api/*. A dispatch function is generated which
+matches RPC API method names with public API functions, converting/validating
+arguments and return values back to msgpack.
 
 Client libraries (|api-client|s) normally provide wrappers that hide
 msgpack-rpc details from application developers. The wrappers can be
@@ -184,7 +184,7 @@ Vim class with methods mapped to functions prefixed with `vim_`.
 ==============================================================================
 5. Types							    *rpc-types*
 
-The Nvim C API uses custom types for all functions. |nvim-api-types|
+The Nvim C API uses custom types for all functions. |api-types|
 For the purpose of mapping to msgpack, the types can be split into two groups:
 
   - Basic types that map natively to msgpack (and probably have a default