feat: add function to auto read and apply .nvmrc file with fnm

oh-my-custom-zsh.zsh

@@ -182,3 +182,36 @@ theme() {
   fi
   echo "Theme folder doesn't exist!"
 }
+
+# Auto read and apply .nvmrc with fnm
+applynvmrc() {
+  if [ ! -f ".nvmrc" ]; then
+    return
+  fi
+
+  local node_version="$(node --version | grep -o '[^-]*$')"
+  local nvmrc_node_version="$(cat .nvmrc | tr -d " \t\n\r" )"
+
+  if [ ! -n $nvmrc_node_version ]; then
+    return
+  fi
+
+  case "$(tr -dc '.' <<<"$nvmrc_node_version" | awk '{ print length; }')" in
+    1)
+      if [ "$(echo $node_version | cut -d. -f1).$(echo $node_version | cut -d. -f2)" != $nvmrc_node_version ]; then
+        fnm use $nvmrc_node_version
+      fi
+      ;;
+    2)
+      if [ $node_version != $nvmrc_node_version ]; then
+        fnm use $nvmrc_node_version
+      fi
+      ;;
+    *)
+      if [ "$(echo $node_version | cut -d. -f1)" != $nvmrc_node_version ]; then
+        fnm use $nvmrc_node_version
+      fi
+      ;;
+  esac
+}
+chpwd_functions=(${chpwd_functions[@]} "applynvmrc")