Document that the spec uses RFC 2119

[HarHarLinks]

Contributed with my community hat on.

I added it to the index because the index itself already starts using RFC 2119 language in section 3.

Pull Request Checklist

Resolves #1927

• Pull request includes a changelog file
• Pull request includes a sign off
• Pull request is classified as 'other changes'

Preview: https://pr1928--matrix-spec-previews.netlify.app

[HarHarLinks]

could you clarify where I should put the newsfragment for a change to the index?

Update: https://matrix.to/#/#matrix-spec:matrix.org suggests adding it to all.

[richvdh]

some minor edits

[richvdh]

"Bindingness" is rather an awkward word!

Can we just say something like:

Suggested change

	### Bindingness of requirements
	As a standards document, the Matrix Spec needs to signify the bindingness of the
	individual features, APIs, procedures, or other requirements it describes.
	### Use of RFC2119 keywords

... and omit the first paragraph, which I don't think adds much value?

[HarHarLinks]

I tried to be more generic and may have ended up with a mangled Germenglish version. How do you think about something slightly more general and introductory than jumping straight to RFC 2119 in the title?

Suggested change

	### Bindingness of requirements
	As a standards document, the Matrix Spec needs to signify the bindingness of the
	individual features, APIs, procedures, or other requirements it describes.
	### Requirement levels

---

I'm slightly confused by the spelling in your proposal: Is it correct that contrary to MSCs, RFCs use a space before the number? RFC 2119 does where it references itself.

[richvdh]

I'm slightly confused by the spelling in your proposal: Is it correct that contrary to MSCs, RFCs use a space before the number?

No, that's just me being a crank. The space is correct.

[richvdh]

LGTM. Thanks!