new version GuitarMidi-lv2 v2.1

Hi, version 2.1 is out with some improvements.
## CPU performance
   - implemented performant filterbank
   - removed dspfilters submodule

## Detection
   - added note detection volume to reduce false positives

## Other improvments and new contributors
By Tomtiger66: Fix hardcoded tflite path: use LV2 bundle_path instead
of /usr/lib/lv2=20

Get it at
https://github.com/geraldmwangi/GuitarMidi-LV2/releases/tag/v2.1

Regarding the mod dwarf, I=E2=80=99ve improved the plugins runtime performa=
nce
on the cpu so that it runs on the mod without xruns

However latency is still very high ~50ms. This is due to the neural net
having ~800k parameters. I cant release it this way. I have thought
about the implementation of a monophonic but that is an entirely
different model that needs to be designed, trained and tested. taking
time away from my task to provide rock solid polyphony for linux and
linux-powered devices. And in some way this move feels backward since
the core tenet of the plugin is that you should be able to seemlessly
switch from solos to chords and this I have achieved.

There is hope though. I have ordered the coral usb accelerator
https://botland.store/google-coral/16911-google-coral-usb-accelerator-edge-=
tpu-ml-arm-cortex-m0-193575021935.html
for which tensorflow lite has support, I think this is the way forward,
my plan is anyway to support new guitar gear that have tensor
processing units. Thanks for your understanding=20
Regards,=20
Gerald