Add exercism completion for zsh

shell/+zsh/completions/_exercism

@@ -0,0 +1,41 @@
+#compdef exercism
+#autoload
+
+_exercism() {
+    local curcontext="$curcontext" state line
+    typeset -A opt_args
+
+    local -a options
+    options=(debug:"Outputs useful debug information."
+             configure:"Writes config values to a JSON file."
+             demo:"Fetches a demo problem for each language track on exercism.io."
+             fetch:"Fetches your current problems on exercism.ios well as the next unstarted problem in each language."
+             restore:"Restores completed and current problems on from exercism.iolong with your most recent iteration for each."
+             submit:"Submits a new iteration to a problem on exercism.io."
+             unsubmit:"Deletes the most recently submitted iteration."
+             tracks:"List the available language tracks"
+             download:"Downloads and saves a specified submission into the local system"
+             help:"Shows a list of commands or help for one command")
+
+    _arguments -s -S \
+        {-c,--config}"[path to config file]"    \
+        {-d,--debug}"[turn on verbose logging]" \
+        {-h,--help}"[show help]"                \
+        {-v,--version}"[print the version]"     \
+        '(-): :->command'                       \
+        '*: :'                                  \
+        && return 0;
+
+    case $state in
+        (command)
+            _describe 'commands' options ;;
+        *)
+        case $words[2] in
+            *submit)
+                _files
+                ;;
+        esac
+    esac
+}
+
+_exercism