Adds link to GitHub on main page.

There was no obvious link to GitHub on the main page.  I eventually found it in the linting badge, but it was very non-obvious there.  Everything else in the docs just links to various places *besides* the GitHub repository.

docs/index.md

@@ -4,7 +4,7 @@
 [![Tests](https://github.com/agencyenterprise/neurotechdevkit/actions/workflows/test.yml/badge.svg)](https://github.com/agencyenterprise/neurotechdevkit/actions/workflows/test.yml)
 [![Gallery examples](https://circleci.com/gh/agencyenterprise/neurotechdevkit.png?style=shield)](https://circleci.com/gh/agencyenterprise/neurotechdevkit)
 
-The [_Neurotech Development Kit_ (NDK)](https://agencyenterprise.github.io/neurotechdevkit/) is an open-source, community-driven software library designed to lower the barrier of entry to the next generation of neurotechnology for current researchers and companies. It also enables software developers without access to hardware and human subjects to solve open problems in the field. The initial release of NDK provides support for transcranial focused ultrasound stimulation, along with comprehensive documentation, API flexibility, and 2D/3D visualizations. Future areas of interest may include photoacoustic and optical whole-brain imaging.
+The [_Neurotech Development Kit_ (NDK)](https://agencyenterprise.github.io/neurotechdevkit/) is an [open-source](https://github.com/agencyenterprise/neurotechdevkit), community-driven software library designed to lower the barrier of entry to the next generation of neurotechnology for current researchers and companies. It also enables software developers without access to hardware and human subjects to solve open problems in the field. The initial release of NDK provides support for transcranial focused ultrasound stimulation, along with comprehensive documentation, API flexibility, and 2D/3D visualizations. Future areas of interest may include photoacoustic and optical whole-brain imaging.
 
 As a community-driven project, we encourage you to contribute code, feedback, and features to help accelerate the development of transformative neurotechnology.