fix docs link + some theme fixes

discord button readability fell down a cliff, so i had to do something
about it

Author: NSPC911

src/font/CaskaydiaMono_Regular.ttf

@@ -43,7 +43,7 @@ <h3>Pages:</h3>
         <button oreui-type="button" oreui-color="green" class="bpbutton" onclick="document.location='https://becomtweaks.github.io/behaviour-packs'">
           Behaviour Packs
         </button>
-        <button oreui-type="button" oreui-color="green" class="docbutton" onclick="document.location='https://becomtweaks.github.io/docs'">
+        <button oreui-type="button" oreui-color="green" class="docbutton" onclick="document.location='https://becomtweaks.gitbook.io/docs'">
           Docs
         </button>
         <button oreui-type="button" oreui-color="green" class="discobutton" onclick="document.location='https://becomtweaks.github.io/discord'">