remove difftool

Better command is now part of neovim itself: neovim/neovim#35448

Signed-off-by: Tomas Slusny <slusnucky@gmail.com>

Author: deathbeam

README.md

@@ -74,37 +74,6 @@ Command-line autocompletion
 ## diagnostics
 Automatically disable `DiagnosticUnnecessary` highlighting for code under cursor.
 
-## difftool
-`DiffTool <left> <right>` command for integration with `git difftool` and `git difftool --dir-diff`.
-
-### Default config
-```lua
-{
-    rename = {
-        detect = true, -- whether to detect renames, can be slow on large directories so disable if needed
-        similarity = 0.5, -- minimum similarity for rename detection
-        max_size = 1024 * 1024, -- maximum file size for rename detection
-    },
-    highlight = {
-        A = 'DiffAdd', -- Added
-        D = 'DiffDelete', -- Deleted
-        M = 'DiffText', -- Modified
-        R = 'DiffChange', -- Renamed
-    },
-}
-```
-
-### Usage
-Add this to your `gitconfig`:
-
-```ini
-[diff]
-    tool = nvim_difftool
-
-[difftool "nvim_difftool"]
-    cmd = nvim -c \"DiffTool $LOCAL $REMOTE\"
-```
-
 ## httpyac
 Simple plugin for running http files using [httpyac](https://httpyac.github.io/)