Fix Sector linking from the config file to read the docs

[trevorb1]

Type of documentation issue

Other

Issue Description

The config file has two headers called sector; one for the wildcard and one for the sector configuration options. This is an issue for read the docs as it looks for sector to automatically link configuration options. Right now I get around this by copying over the sector config options.

Link to existing documentation

https://github.com/PyPSA/pypsa-usa/blob/362360e34c51af86fe156e1a28dc0d560f1288a2/docs/source/config-configuration.md?plain=1#L200-L211

Suggested Update

Probably just changing the sector options (not the wildcard) to sectors will make the most sense. I guess it may be a little more work than just changing the wildcard, but probably makes more intuitive sense.

Additional Info

No response