Improve release instructions

[SamantazFox]

As requested by unixfox, this improves the release process instructions. I also fixed some typos here and there.

[syeopite]

What do you think should be considered as a patch release over a standard minor release?

[syeopite]

How do you think we should document the stray commits that occasionally get pushed without an associated PR?

[syeopite]

There's somewhat of a convention in how each PR is listed so maybe we could document that?

Here's how I understand it at least:

Suggested change

	Do not forget to list **ALL** the PRs that have been merged since the last
	Do not forget to list **ALL** the PRs that have been merged since the last
	release, with the proper links.
	The pull requests should be listed from the most recently merged to the oldest. Each entry should roughly follow this template:
	`{Summary} (#{PR Number}, by/thanks @{Author})`
	If the pull request is by a core team member they should be attributed with `by @{Author}`
	Otherwise the PR author should be attributed with `thanks @{Author}`

[SamantazFox]

How do you think we should document the stray commits that occasionally get pushed without an associated PR?

Hmm, that's a good question. For "revert" commits, I think we can simply remove the associated PR from the list, or at least mark it as (reverted). For the rest I don't know. That's the reason why I'd like to enfore the "always make PRs" policy, and keep stray commits to fix bugs/typos in a recently merged PR.

There's somewhat of a convention in how each PR is listed so maybe we could document that?

Yeah, That's a good idea!

Here's how I understand it

That's it, except that I used the PR title, rather than a summary. I often had to reword PRs on github to make the title more meaningful than fix bug #123...

[SamantazFox]

What do you think should be considered as a patch release over a standard minor release?

This is explained in the preamble. IIRC that's what we agreed upon back then, but we can always improve it if needed.