Include title parameter in the API example

Title should be included as one of the post fields in the example so that people are aware of it, and also aware that NOT including it incurs a significant (10x) performance penalty.

See related issue https://github.com/YOURLS/YOURLS/issues/1454
Reworked @nicwaller's patch
Added @OmmJan's VB.Net in the readme. Closes #1449