Add support for specifying base URL

[bitgopatmcl]

Adds support for emitting the servers section of an OpenAPI spec by annotating h.apiSpec objects with the appropriate JSDoc tags. For example:

    /** An API spec
     *
     * @url /api/v1
     **/
    export const test = h.apiSpec({
      'api.test': {
        get: h.httpRoute({
          path: '/test',
          method: 'GET',
          request: h.httpRequest({}),
          response: {
            200: t.string,
          },
        })
      }
    });

Will result in something like this in the emitted OpenAPI:

servers:
- description: An API spec
  url: /api/v1

[ericcrosson-bitgo]

It looks like we're trying to support a use case of specifying multiple servers. Should we add a test for that use-case?

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[github-actions]

🎉 This PR is included in version @api-ts/[email protected] 🎉

The release is available on npm package (@latest dist-tag)

Your semantic-release bot 📦🚀

[github-actions]

🎉 This PR is included in version @api-ts/[email protected] 🎉

The release is available on npm package (@latest dist-tag)

Your semantic-release bot 📦🚀