Robots noindex and spelling

The URL to the deployment script may be leaked to a search engine through someone's negligence. This has already taken place a few times: https://www.google.com/search?q=%22Simple+PHP+Git+deploy+script%22. The indexing of these pages is obviously not desirable. We can try to mitigate the possible negative effects of this by supplying relevant instructions to robots in the form of a meta tag.

I also corrected a misspelling.

I didn't know exactly how you prefer pull requests to be performed, so feel free to make the same changes if you don't want to merge this right into the master branch. Thanks for your efforts on this script - it is very helpful!