Add Bandcamp plugin to Lidarr plugins page

[jtstothard]

Adds Bandcamp by jtstothard as a community plugin.

Bandcamp indexer and download client for Lidarr nightly. Searches the user's collection for purchased albums and downloads them. Cookie-based auth using the identity cookie. Only works with music you own.

18 releases published, CI builds and tests pass on every push.

[augustuen]

Why did you open a new PR?

[jtstothard]

Why did you open a new PR?

Complete mistake, sorry!

[jtstothard]

The extra commits fix pre-existing issues that pre-commit.ci was auto-patching on every push:

• markdownlint: bare fenced code blocks in tips-and-tricks.md (lines 25, 40) and importing-existing-library.md (lines 41, 47) — added text language tags. Table separator style in tips-and-tricks.md lines 110, 237.
• typos: truncated lines from upstream — succes → success rate, thi → this page, mis-linked → mislinked.
• trailing-whitespace / end-of-file-fixer / blank-line removal: pre-commit.ci was stripping double blanks and adding missing newlines across several lidarr docs.

All hooks pass clean now, so no more auto-fix commits. The only change to lidarr/plugins.md is the Bandcamp plugin entry.