Simplify releasing
As raised by @duckontheweb in https://github.com/stac-utils/stactools/pull/241#pullrequestreview-890226944, our current release procedure is rather cumbersome (see RELEASING.md). Tools such as https://github.com/dmerejkowsky/tbump or https://github.com/c4urself/bump2version could help simplify the process. We should research options and decide whether it is worth it to update our release architecture.
I tried implementing bump2version in PySTAC as part of the upcoming release, but am blocked by c4urself/bump2version#235 in automating the changes to the CHANGELOG.
That'd make this decision easy, since the stactools default is "do what PySTAC is doing." :-D