Add an {allowSubPaths: true} option to the deconstruct method.

This allows deconstructing URLs/paths where they match the template but include additional sub-paths e.g.

const url = createTSURL(['user', requiredString('userId')], {
  baseUrl: 'https://server.com',
  basePath: '/api',
  trailingSlash: false,
});

url.deconstruct('https://server.com/api/user/123/posts/123');
// throws an error

url.deconstruct('https://server.com/api/user/123/posts/123', {
  allowSubPaths: true,
});
// returns { urlParams: { userId: '123' }, queryParams: {} }

This PR also converts ReadonlyArray<whatever> to readonly whatever[] and makes some changes to how param types are inferred so that instead of inferring a LOT of interfaces (one for each value type: string, number, boolean, etc) we only infer a single interface for required parts and another for optional parts.

This means that instead of ending up with types like { requiredString: string } & { requiredNumber: number } & {} & {} & {} & {}... etc { optionalNumber: number } & {} . We just end up with { requiredString: string, requiredNumber: number } & { optionalNumber: number }

Some minor fixes to documentation.