Add our patch file naming standard to project page

There was an issue a while ago #1036268: Decide on naming convention for patch files where we discussed and agreed on a preferred naming convention for patches to scheduler. I think it would be helpful to add our standard to the project front page, so that it is easy for everyone to adhere. When testing multiple patches over many issues, it is so much easier if they all have the same naming format. Something like this for the front page:

When making a patch for Scheduler please name the file with the following format:
issuenumber_commentnumber{.scheduler}.description.patch{.txt}
The {.scheduler} and {.txt} are optional.

The important bit is starting with the issue number, followed by _ then comment number. Is this ok?

Jonathan