Path component in client_id considered optional

[cjw6k]

According to https://indieauth.spec.indieweb.org/#client-identifier

Client identifier URLs ... MUST contain a path component

Example clients which provide no path component in client_id:

1. indiebookclub.biz
2. indigenous.realize.be (Indigenous for Android, as of 2020-06-16)
3. omnibear.com
4. teacup.p3k.io

It is understood that most IndieAuth servers permit clients with valid-in-common-usage client_ids.

Suggestion: modify the spec to match the common usage.