Recent Activity readme

[JordiNodeJS]

I add a tag in README.md to spot the most recently activity in the repo such as: Closed, Commented, Opened issue, Opened PR. To do this I'v added a <!--START_SECTION:activity--> to file README, and I've created a github action called: update-readme.yml which update readme file each hour rewrite the readme with the newest info in the repo.

First time I create a Github Action and write a file yml so I apreciate if you check out if ieverything's fine.