fix(git)!: rename `git mergetool` aliases to `gmtl*` (#9154)

BREAKING CHANGE: the `gmt` alias conflicts with the Generic Mapping Tools command.
For that, the `gmt` alias has been renamed to `gmtl`, and `gmtvim` has been renamed to
`gmtlvim` for consistency.

Fixes #9154

plugins/git/README.md

@@ -108,8 +108,8 @@ plugins=(... git)
 | glp                  | git log --pretty=\<format\>                                                                                                      |
 | gm                   | git merge                                                                                                                        |
 | gmom                 | git merge origin/$(git_main_branch)                                                                                              |
-| gmt                  | git mergetool --no-prompt                                                                                                        |
-| gmtvim               | git mergetool --no-prompt --tool=vimdiff                                                                                         |
+| gmtl                 | git mergetool --no-prompt                                                                                                        |
+| gmtlvim              | git mergetool --no-prompt --tool=vimdiff                                                                                         |
 | gmum                 | git merge upstream/$(git_main_branch)                                                                                            |
 | gma                  | git merge --abort                                                                                                                |
 | gp                   | git push                                                                                                                         |

plugins/git/git.plugin.zsh

@@ -221,8 +221,8 @@ alias glp="_git_log_prettily"
 
 alias gm='git merge'
 alias gmom='git merge origin/$(git_main_branch)'
-alias gmt='git mergetool --no-prompt'
-alias gmtvim='git mergetool --no-prompt --tool=vimdiff'
+alias gmtl='git mergetool --no-prompt'
+alias gmtlvim='git mergetool --no-prompt --tool=vimdiff'
 alias gmum='git merge upstream/$(git_main_branch)'
 alias gma='git merge --abort'