docs: replace <pre> with ``` (#25136)

runtime/lua/vim/_meta/json.lua

@@ -1,8 +1,8 @@
---- @meta
+---@meta
 
 -- luacheck: no unused args
 
---- @defgroup vim.json
+---@defgroup vim.json
 ---
 --- This module provides encoding and decoding of Lua objects to and
 --- from JSON-encoded strings. Supports |vim.NIL| and |vim.empty_dict()|.
@@ -14,24 +14,23 @@
 --- - Decodes empty array as `{}` (empty Lua table).
 ---
 --- Example:
---- <pre>lua
---- :lua vim.print(vim.json.decode('{"bar":[],"foo":{},"zub":null}'))
---- --> { bar = {}, foo = vim.empty_dict(), zub = vim.NIL }
---- </pre>
---- Parameters: ~
----   • {str}    Stringified JSON data.
----   • {opts}   Options map keys:
----              • luanil: { object: bool, array: bool }
----                • `luanil.object=true` converts `null` in JSON objects to
----                  Lua `nil` instead of `vim.NIL`.
----                • `luanil.array=true` converts `null` in JSON arrays to Lua
----                  `nil` instead of `vim.NIL`.
---- @param str string
---- @param opts? table<string, any>
---- @return any
+---
+--- ```lua
+--- vim.print(vim.json.decode('{"bar":[],"foo":{},"zub":null}'))
+--- -- { bar = {}, foo = vim.empty_dict(), zub = vim.NIL }
+--- ```
+---
+---@param str string Stringified JSON data.
+---@param opts? table<string,any> Options table with keys:
+---                                 - luanil: (table) Table with keys:
+---                                   * object: (boolean) When true, converts `null` in JSON objects
+---                                                       to Lua `nil` instead of |vim.NIL|.
+---                                   * array: (boolean) When true, converts `null` in JSON arrays
+---                                                      to Lua `nil` instead of |vim.NIL|.
+---@return any
 function vim.json.decode(str, opts) end
 
 --- Encodes (or "packs") Lua object {obj} as JSON in a Lua string.
---- @param obj any
---- @return string
+---@param obj any
+---@return string
 function vim.json.encode(obj) end