Hm, we need a good writeup on this for the docs!
I'm not fully qualified to answer your questoins because I've made very few plugins, but FWIW;
While it's not about "publishing" per se but Andreas Hahns
Tinka plugin packer, might help to get some of the things right for publication. While very useful, I'd say it still needs some improvements before it is fully functional though. (In spite of the fairly recent update. I experienced this just yesterday actually.)
Upload wherever you want... but I warmly recommend TiddlySpot because everyone is familiar with it and it is a popular place. Some publish their plugins on github but it is always unclear for me (and surely others) how exactly to install it and github is a bit scary overall. Others have it in some cryptic dropbox folder that IMO feels unreliable in that the link to it could disappear from access. Also one can never guess the url for it like with TiddlySpot where it is always
xxx.tiddlyspot.comIf you include a readme tiddler or maybe even an icon, make sure to title those like so
$:/...thepluginname.../readme
$:/...thepluginname.../icon
not e.g
$:/...thepluginname.../Readme
$:/...thepluginname.../README
The readme and the icon will then show in the plugin library, i.e the readme tab will be active/open by default and (which I figured out just yesterday) this is how you get an icon to show.
If you use Tinka, I also recommend mentioning the name of the plugin in the Description field because this is what is shown in big letters next to the icon in the plugin library. (e.g for the SideEditor, the description is:
SideEditor - a "live" editor next to your tiddler)
Note that you don't need to package things in a plugin. You can also just have multiple separate tiddlers that people drag over one at a time (obviously you miss out on the plugin overwrite-protection then).
Also, send a ping to
Erwan and you'll be included in the Community Search aggregator
http://erwanm.github.io/tw-community-search/<:-)