checklist for people upgrading to genome-grist v0.9.0

[ctb]

I plan to cut a new release pretty soon, but we've made a few changes that will catch people by surprise if they upgrade - so writing this down to include instructions in the release notes.

also this can serve as a reminder to myself to update the mkdocs site upon release 🙄

changes since 0.8.x series -

• if we remove the abundtrim step per [MRG] remove abundance trimming from the default genome-grist workflow #199, then the details on how to provide your own metagenomes will change. We should suggest people (a) turn off SRA download and (b) rename their abundtrim files.
• in [MRG] change column names in mapping summary files; add count of mapped reads. #209 and [MRG] rename avg_unique_mapped_coverage to effective_coverage #219, we changed a bunch of column names in the mapping summary output, but then also helpfully documented them! so point at the new documentation! Users will want to regenerate their mapping/*.summary.csv and leftover/*.summary.csv files.
• in [MRG] switch to gzipped sourmash input/output files #213 we switched to gzipping the output files from sourmash. So if you want to avoid rerunning prefetch and gather, you'll need to gzip them. We should provide instructions!

people to inform of release: @jeanzzhao, @hehouts, @jessicalumian

[ctb]

released! advice in #225.