Install node version from .nvmrc if we don't have it

zsh-nvm.plugin.zsh

@@ -161,9 +161,10 @@ _zsh_nvm_auto_use() {
   if [[ -n "$nvmrc_path" ]]; then
     local nvmrc_node_version=$(nvm version "$(cat "${nvmrc_path}")")
 
-    if [[ "$nvmrc_node_version" != "N/A" ]] && [[ "$nvmrc_node_version" != "$node_version" ]]; then
-      nvm use
-      export NVM_AUTO_USE_ACTIVE=true
+    if [[ "$nvmrc_node_version" != "N/A" ]]; then
+      [[ "$nvmrc_node_version" != "$node_version" ]] && nvm use && export NVM_AUTO_USE_ACTIVE=true
+    else
+      nvm install && export NVM_AUTO_USE_ACTIVE=true
     fi
   elif [[ "$node_version" != "$(nvm version default)" ]] && [[ "$NVM_AUTO_USE_ACTIVE" = true ]]; then
     echo "Reverting to nvm default version"