fix(docs): update accounts documentation to clarify aspects

[theo-o]

Proposed changes

• Update CSL Account Documentation to reflect changes for SY2020-21 and clarify some vocab and steps.

Brief description of rationale

Some parts of the current accounts docs are unclear.

[coveralls]

Coverage decreased (-0.007%) to 55.196% when pulling b4c28d4 on docs into 4a75e9c on dev.

[Laur04]

Should we add a note about webmail sometimes providing an Unknown error at login? It's been doing that a lot for me recently and I would rather not get a bunch of emails tomorrow about webmail showing that error. It will work if you just try again a couple of times.

[theo-o]

Should we add a note about webmail sometimes providing an Unknown error at login? It's been doing that a lot for me recently and I would rather not get a bunch of emails tomorrow about webmail showing that error. It will work if you just try again a couple of times.

Not sure about whether account documentation is the right place to do this.

[theo-o]

Errors with build on push can be safely ignored.

[etnguyen03]

Otherwise, LGTM

[etnguyen03]

Suggested change

	<li>Click the "Authenticate" button. If you are already authenticated, you may be immediately proceed to step 4.</li>
	<li>Click the "Authenticate" button. If you are already authenticated to your FCPS Google account, you may be skipped to step 4.</li>

"you may be immediately proceed" is not grammatically correct.

[Laur04]

Should we add a note about webmail sometimes providing an Unknown error at login? It's been doing that a lot for me recently and I would rather not get a bunch of emails tomorrow about webmail showing that error. It will work if you just try again a couple of times.

Not sure about whether account documentation is the right place to do this.

Probably right, maybe link to guides.tj for troubleshooting and mention it somewhere there?