Indexing Docs/Wiki should be updated

[gwiedeman]

It looks to me like the Indexing EAD in ArcLight wiki was mostly written before the Traject workflow. It does document how to index with Traject, but its a bit hidden on the bottom. It now seems to still prioritize rake arclight:index which I don't think works anymore, although if it does that should be a bit clearer. This could clear up some confusion for new users.

Additionally, the Traject indexing commands both on the wiki and the README.md, assume the Traject config file is in lib/arclight/traject/ead2_config.rb. For a lot of setups, that command would raise an error. For example, if you installed a new app with the template, I believe the config file gets stored wherever your gems live. For installs with rvm that might be in ~/.rvm/gems/ruby-3.2.2@gemset-name/gems/arclight-1.0.1/lib/arclight/traject/ead2_config.rb or similar. If would be cool if there was an easier way to manage this in practice to recommend (maybe a symlink?), but if there's no good ideas here that don't cause other issues, just explaining where the config might be via echo $GEM_HOME or similar in the docs might avoid some headaches for new users.

[gwiedeman]

I would actually expect the rails arclight:index task to take the file path as an arg rather than an environment variable, as you're probably not storing that, but its probably not worth what is kind of a breaking change?