Fix some TSDoc/JSDoc lint issues

[shadowspawn]

Pull Request

Problem

Trying lint with eslint-plugin-jsdoc shows lots of warnings.

Solution

Fix the warnings other than:

• prefer @returns over @return. Might change that in future, but only cosmetic and noisy (lots) so left out of this PR.
• @remarks is generating a bogus unrecognised tag warning, as should be allowed in TypeScript (TSDoc)

The fixed errors are things like:

• preferred types, like object rather than Object
• missing @return on function
• @package tag does not allow trailing comment

Not ready to turn on eslint-plugin-jsdoc as there is not yet support for configuring settings.jsdoc.* in flat config (to hopefully fix @remarks), and a problem with the TypeScript declaration in the package which breaks the TypeScript parse of the eslint config file.