Add configuration options

[PeeHaa]

• [x] expose address(es)
• [x] expose port
• [x] allow a way to add multiple origins

[PeeHaa]

Expose port and multiple origins are fixed in https://github.com/ekinhbayar/gitamp/commit/c48f502c8a66c02b991c0331dc3c7fa3fbdc9e35.

Do we want to add a config for the expose address too or just keep it hardcoded to the wildcard * @ekinhbayar ?

[PeeHaa]

Expose address is fixed in https://github.com/ekinhbayar/gitamp/commit/ad5e505918f5f65fd3b73f020280f6bd55a83047