git: add tag aliases

Originally submitted in https://github.com/sorin-ionescu/prezto/pull/1094

modules/git/README.md

@@ -288,6 +288,11 @@ zstyle ':prezto:module:git:alias' skip 'yes'
   - `gSu` fetches and merges the latest changes for all submodule.
   - `gSx` removes a submodule.
 
+### Tag
+
+  - `gt` lists tags or creates tag.
+  - `gtl` lists tags matching pattern.
+
 ### Working directory
 
   - `gws` displays working-tree status in the short format.

modules/git/alias.zsh

@@ -250,6 +250,10 @@ if ! zstyle -t ':prezto:module:git:alias' skip 'yes'; then
   alias gSu='git submodule foreach git pull origin master'
   alias gSx='git-submodule-remove'
 
+  # Tag (t)
+  alias gt='git tag'
+  alias gtl='git tag -l'
+
   # Working Copy (w)
   alias gws='git status --ignore-submodules=${_git_status_ignore_submodules} --short'
   alias gwS='git status --ignore-submodules=${_git_status_ignore_submodules}'