Update index.rst

Switch dl-cpp link to RTD

source/index.rst

@@ -13,6 +13,6 @@ This is just the homepage, you can find more information at the following pages:
    Why-Dripline
    The Guides and Walthroughs <https://controls-guide.readthedocs.io/en/latest/>
    The Dripline Protocol Documentation <https://dripline.readthedocs.io/en/latest/>
-   The C++ Implementation, dripline-cpp <https://driplineorg.github.io/dripline-cpp>
+   The C++ Implementation, dripline-cpp <https://dripline-cpp.readthedocs.io/en/latest/>
    The Python Implementation, dripline-python <https://dripline-python.readthedocs.io/en/latest/>
    Contact-Us