add script for easier updating

[paresy]

Updated against https://github.com/discourse/discourse/commits/293fd1f743b1c8165e1cd06b1169134197a231f7

[communiteq]

Thank you for providing an updated version and I think it's a good idea to include a script.

I would like to suggest two changes:

• can you make it so that it cleans up the discourse directory if it did not exist when the script was started
• can you change the echo "" > common/head_tag.html to echo -n so there is no blank line

[paresy]

Thank you for the fast response. I added the -n but i am unsure about your second comment.

I though about adding rm -R discourse, but opted for a "faster" update cycle which should only pull relevant changes instead of a full clone which would have been required after removing the folder. Also rm always feels dangerous :-) An alternative would be to only clone if the folder does not exist and leave the git pull to the end user if he wants to?

Just my thoughts - i am happy to do the rm, if you prefer.

Another quick idea: Would you like to have a GitHub Action Job, which would automatically run & commit changes every X days? This would keep the Repo fresh without any manual steps. I thought about this action here: https://github.com/marketplace/actions/add-commit

[paresy]

Just wanted to followup to get it off my open PR list.
I updated the PR to only include the script and merged your changed from master.