Convert version and help into options

Instead of clobbering the actions with both version and help, use
options instead. They are also going to be used for subcommands (e.g.
omf list --help) once they support options.

pkg/omf/cli/omf.help.fish

@@ -12,9 +12,11 @@ function omf.help
           "(omf::em)"n"(omf::off)"ew  Create a new package from a template.
        "(omf::em)"s"(omf::off)"ubmit  Submit a package to the registry.
         "(omf::em)"q"(omf::off)"uery  Query environment variables.
-       "(omf::em)"h"(omf::off)"elp  Display this help.
-    "(omf::em)"v"(omf::off)"ersion  Display version.
       "(omf::em)"destroy"(omf::off)"  Uninstall Oh My Fish.
 
+  "(omf::dim)"Options"(omf::off)"
+       "(omf::em)"--h"(omf::off)"elp  Display this help.
+    "(omf::em)"--v"(omf::off)"ersion  Display version.
+
   For more information visit → "(omf::em)"git.io/oh-my-fish"(omf::off)\n
 end

pkg/omf/omf.fish

@@ -39,7 +39,7 @@ function omf -d "Oh My Fish"
   end
 
   switch $argv[1]
-    case "v" "ver" "version"
+    case "-v*" "--v*"
       omf.version
 
     case "q" "query"
@@ -54,7 +54,7 @@ function omf -d "Oh My Fish"
           return $OMF_INVALID_ARG
       end
 
-    case "h" "help"
+    case "-h*" "--h*" "help"
       omf.help
 
     case "l" "li" "lis" "lst" "list"