docs(marketplace): five statements no longer match the code #760

website#672 describes tag following of connected repositories accurately. Five other statements in content/en/docs/next/marketplace/ became wrong after later changes in cozystack. Lines are from main today.

1. _index.md L40 and connecting.md L20: "Tapping itself installs nothing." Since cozystack#4308 connecting creates registration Package, and Package reconciler installs its components (ensureRegistration in tapmaterializer_reconciler.go).
2. _index.md L36: "the ApplicationDefinition resources a repository registers are not checked against the core catalog." Since cozystack#4424 second definition for a kind that another definition declares is refused at admission, and one rule (appdefowner) decides which definition manages a kind. Admission is best effort (failurePolicy: Ignore), the rule in code is the guard.
3. connecting.md L112: "cozypkg add ... which is how the paired registration chart puts the application in the catalog." Registration happens on connect, not through add.
4. connecting.md L145: dashboard disconnect "does not remove already-installed applications." It removes registration Package, its HelmReleases and its ApplicationDefinitions.
5. connecting.md L135: untap "refuses and deletes nothing" when a Package of that name is installed. It removes tap-managed registration Package of that name without --yes, only Package that is not the managed registration blocks the untap (runUntap in cmd/cozypkg/cmd/tap.go).

One pending change touches same pages, what happens to install-on-connect, so final text for 1, 3, 4 and 5 should be written after that is decided.