Add git alias for gcM (GPG-sign the commit)

modules/git/README.md

@@ -53,6 +53,7 @@ Aliases
   - `gc` records changes to the repository.
   - `gca` stages all modified and deleted files.
   - `gcm` records changes to the repository with the given message.
+  - `gcM` same as `gcm` but adds a GPG signature to the commit.
   - `gco` checks out a branch or paths to work tree.
   - `gcO` checks out hunks from the index or the tree interactively.
   - `gcf` amends the tip of the current branch using the same log message as

modules/git/alias.zsh

@@ -45,6 +45,7 @@ alias gbS='git show-branch -a'
 alias gc='git commit --verbose'
 alias gca='git commit --verbose --all'
 alias gcm='git commit --message'
+alias gcM='git commit --gpg-sign --message'
 alias gco='git checkout'
 alias gcO='git checkout --patch'
 alias gcf='git commit --amend --reuse-message HEAD'