Add a section on how to depend on CC:T

It's not immediatly obvious where our maven repository is.

README.md

@@ -45,3 +45,22 @@ ## Contributing
  - **Test your changes:** `./gradlew runClient` (or run the `GradleStart` class from your IDE).
 
 If you want to run CC:T in a normal Minecraft instance, run `./gradlew build` and copy the `.jar` from `build/libs`.
+
+## Using
+If you want to depend on CC:Tweaked, we have a maven repo. However, you should be wary that some functionality is only
+exposed by CC:T's API and not vanilla ComputerCraft. If you wish to support all variations of ComputerCraft, I recommend
+using [cc.crzd.me's maven](https://cc.crzd.me/maven/) instead.
+
+```groovy
+dependencies {
+  maven { url 'https://squiddev.cc/maven/' }
+}
+
+dependencies {
+  implementation "org.squiddev:cc-tweaked:${mc_version}-${cct_version}"
+}
+```
+
+You should also be careful to only use classes within the `dan200.computercraft.api` package. Non-API classes are
+subject to change at any point. If you depend on functionality outside the API, file an issue, and we can look into
+exposing more features.