add zig stuff

mygvm/mygvm

@@ -148,11 +148,23 @@ elif [[ $1 == 'uninstall' ]]; then
 elif [[ $1 == 'install' ]]; then
     install_version $2
 elif [[ $1 == 'use' ]]; then
-    check_exists $2
-    if [[ $exists == true ]]; then
-        link_version $2
+    if [[ $2 == 'local' ]]; then
+        go_mod_json=$(go mod edit -json)
+        if [[ $? == 1 ]]; then
+            echo "unable to find go.mod"
+            echo "using $(go version)"
+            exit 1
+        else
+            version_to_use=go$(jq -r .Go <<< $go_mod_json)
+        fi
     else
-        prompt_install $2
+        version_to_use=$2
+    fi
+    check_exists $version_to_use
+    if [[ $exists == true ]]; then
+        link_version $version_to_use
+    else
+        prompt_install $version_to_use
     fi
     install_modules
 elif [[ $1 == 'modules' ]]; then