Added a first version of the 12DB equalizer

Can guarrantee that this version is wrong. Work continues...
Added a first version of the 12DB equalizer

Still very much wrong
Created a more customizable IIR filter
Added comments and made small adjustments

The code is now much clearer on what it does
Added first version of the full equalizer
Completed first version of a fully working equalizer

Unfortunatly, the coefficients are not fully correct at the moment
All coefficients now inserted to Equalizer
Addad documentation for multiplier block
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Started on a testbench for multiplier
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1337
Pad with ones at binals for negative numbers
1337 HAXXOR
Replaced old files.
Added Niklas multiplier cause git is acting up
Adder is now saturated
Fixed saturation adder
Fixed word length problem with multiplier