docs: telescope.nvim spelling and grammar fixes (#2325)

Corrects the following issues:
- article agreement
- spelling

doc/telescope.txt

@@ -3287,7 +3287,7 @@ PREVIEWERS                                                *telescope.previewers*
 
 Provides a Previewer table that has to be implemented by each previewer. To
 achieve this, this module also provides two wrappers that abstract most of the
-work and make it really easy create new previewers.
+work and make it really easy to create new previewers.
   - `previewers.new_termopen_previewer`
   - `previewers.new_buffer_previewer`
 
@@ -3316,7 +3316,7 @@ previewers.Previewer()                      *telescope.previewers.Previewer()*
 
     What `:new` expects is listed below
 
-    The interface provides following set of functions. All of them, besides
+    The interface provides the following set of functions. All of them, besides
     `new`, will be handled by telescope pickers.
     - `:new(opts)`
     - `:preview(entry, status)`
@@ -3447,7 +3447,7 @@ previewers.new_buffer_previewer() *telescope.previewers.new_buffer_previewer()*
         recreating that buffer in an action. To access the last buffer number: 
         `require('telescope.state').get_global_key("last_preview_bufnr")`
       - `get_buffer_by_name = function(self, entry)` Allows you to set a unique
-        name for each buffer. This is used for caching purpose.
+        name for each buffer. This is used for caching purposes.
         `self.state.bufname` will be nil if the entry was never loaded or the
         unique name when it was loaded once. For example, useful if you have
         one file but multiple entries. This happens for grep and lsp builtins.
@@ -3543,7 +3543,7 @@ previewers.vim_buffer_vimgrep()    *telescope.previewers.vim_buffer_vimgrep()*
 
 
 previewers.vim_buffer_qflist()      *telescope.previewers.vim_buffer_qflist()*
-    Is the same as `vim_buffer_vimgrep` and only exist for consistency with
+    Is the same as `vim_buffer_vimgrep` and only exists for consistency with
     `term_previewers`.
 
     The preferred way of using this previewer is like this
@@ -3614,7 +3614,7 @@ HISTORY                                              *telescope.actions.history*
 A base implementation of a prompt history that provides a simple history and
 can be replaced with a custom implementation.
 
-For example: We provide a extension for a smart history that uses sql.nvim to
+For example: We provide an extension for a smart history that uses sql.nvim to
 map histories to metadata, like the calling picker or cwd.
 
 So you have a history for:

lua/telescope/actions/history.lua

@@ -11,7 +11,7 @@ local uv = vim.loop
 --- A base implementation of a prompt history that provides a simple history
 --- and can be replaced with a custom implementation.
 ---
---- For example: We provide a extension for a smart history that uses sql.nvim
+--- For example: We provide an extension for a smart history that uses sql.nvim
 --- to map histories to metadata, like the calling picker or cwd.
 ---
 --- So you have a history for:

lua/telescope/previewers/init.lua

@@ -4,7 +4,7 @@
 ---@brief [[
 --- Provides a Previewer table that has to be implemented by each previewer.
 --- To achieve this, this module also provides two wrappers that abstract most
---- of the work and make it really easy create new previewers.
+--- of the work and make it really easy to create new previewers.
 ---   - `previewers.new_termopen_previewer`
 ---   - `previewers.new_buffer_previewer`
 ---
@@ -40,7 +40,7 @@ local previewers = {}
 ---
 --- What `:new` expects is listed below
 ---
---- The interface provides following set of functions. All of them, besides
+--- The interface provides the following set of functions. All of them, besides
 --- `new`, will be handled by telescope pickers.
 --- - `:new(opts)`
 --- - `:preview(entry, status)`
@@ -167,7 +167,7 @@ previewers.qflist = term_previewer.qflist
 ---     `require('telescope.state').get_global_key("last_preview_bufnr")`
 ---   - `get_buffer_by_name = function(self, entry)`
 ---     Allows you to set a unique name for each buffer. This is used for
----     caching purpose. `self.state.bufname` will be nil if the entry was
+---     caching purposes. `self.state.bufname` will be nil if the entry was
 ---     never loaded or the unique name when it was loaded once. For example,
 ---     useful if you have one file but multiple entries. This happens for grep
 ---     and lsp builtins. So to make the cache work only load content if
@@ -258,7 +258,7 @@ previewers.vim_buffer_cat = buffer_previewer.cat
 --- case it's configured that way.
 previewers.vim_buffer_vimgrep = buffer_previewer.vimgrep
 
---- Is the same as `vim_buffer_vimgrep` and only exist for consistency with
+--- Is the same as `vim_buffer_vimgrep` and only exists for consistency with
 --- `term_previewers`.
 ---
 --- The preferred way of using this previewer is like this