feat(docs): "yxx" runs Lua/Vimscript code examples #31904

`yxx` in Normal mode over a Lua or Vimscript code block section will execute the code.

Co-authored-by: Justin M. Keyes <justinkz@gmail.com>

runtime/lua/vim/shared.lua

@@ -959,7 +959,7 @@ do
   ---       function vim.startswith(s, prefix)
   ---         vim.validate('s', s, 'string')
   ---         vim.validate('prefix', prefix, 'string')
-  ---         ...
+  ---         -- ...
   ---       end
   ---     ```
   ---
@@ -979,7 +979,7 @@ do
   ---           age={age, 'number'},
   ---           hobbies={hobbies, 'table'},
   ---         }
-  ---         ...
+  ---         -- ...
   ---       end
   ---     ```
   ---

runtime/lua/vim/treesitter/query.lua

@@ -292,7 +292,7 @@ end)
 ---   - `captures`: a list of unique capture names defined in the query (alias: `info.captures`).
 ---   - `info.patterns`: information about predicates.
 ---
---- Example (select the code then run `:'<,'>lua` to try it):
+--- Example (to try it, use `yxx` or select the code then run `:'<,'>lua`):
 --- ```lua
 --- local query = vim.treesitter.query.parse('vimdoc', [[
 ---   ; query
@@ -983,7 +983,7 @@ end
 ---       -- `node` was captured by the `name` capture in the match
 ---
 ---       local node_data = metadata[id] -- Node level metadata
----       ... use the info here ...
+---       -- ... use the info here ...
 ---     end
 ---   end
 --- end