Add proper Intructions on building FFmpeg Executable binary with static linking

[Shabinder]

This is somewhat a feature request.

As you have mentioned in few issues you plan to do this, I thought having this in the tracker will help.

[Shabinder]

These changes do work if someone wants to do the same until instructions are added:
#49 (comment)

[bugparty]

I will add this option when I have time

[carlonluca]

I needed static build for a project so I added the params: #93.