doc: Various #2898

refs #2895

Helped-by: Bohr Shaw <pubohr@gmail.com>
Helped-by: Justin M. Keyes <justinkz@gmail.com>

[ci skip]

runtime/doc/eval.txt

@@ -5383,7 +5383,7 @@ serverlist()						*serverlist()*
 			:echo serverlist()
 <						{Nvim} *--serverlist*
 		The Vim command-line option `--serverlist` was removed from
-		Nvim, but it can be imitated if needed: >
+		Nvim, but it can be imitated: >
 			nvim --cmd "echo serverlist()" --cmd "q"
 <
 serverstart([{address}])				*serverstart()*

runtime/doc/remote_plugin.txt

@@ -80,7 +80,7 @@ of requests made to it. Here's the plugin source code:
             self.calls += 1
 <
 
-As can be seen, the plugin is implemented using idomatic Python (classes,
+As can be seen, the plugin is implemented using idiomatic Python (classes,
 methods, and decorators). The translation between these language-specific
 idioms to Vimscript occurs while the plugin manifest is being generated (see
 the next section).

runtime/doc/vim_diff.txt

@@ -94,16 +94,17 @@ Highlight groups:
 
 ==============================================================================
 5. Missing legacy features				 *nvim-features-missing*
+				     *if_ruby* *if_lua* *if_perl* *if_mzscheme* *if_tcl*
 
 These legacy Vim features may be implemented in the future, but they are not
 planned for the current milestone.
 
 - vim.bindeval() (new feature in Vim 7.4 Python interface)
-- if_ruby
-- if_lua
-- if_perl
-- if_mzscheme
-- if_tcl
+- |if_ruby|
+- |if_lua|
+- |if_perl|
+- |if_mzscheme|
+- |if_tcl|
 
 ==============================================================================
 6. Removed features					 *nvim-features-removed*