Update doPayment to give example using propertyBag

See merge request documentation/docs/dev!984

APIv3 REST: Document CSRF, backward-compatibility, migration

See merge request documentation/docs/dev!982

Add tip for `qs` parameter of hook_civicrm_links.md. Fixed misspelling.

See merge request documentation/docs/dev!978

Improve description for alterDisplayName

See merge request documentation/docs/dev!981

Add "Pipe Reference"

See merge request documentation/docs/dev!980

Lets focus people in on the stuff they care about!

Remove reference to obsolete upgrade-related function

See merge request documentation/docs/dev!979

document Soft Delete

See merge request documentation/docs/dev!977

Requires select()ing something to show data

See merge request documentation/docs/dev!976