Added note to checkout any submodules before building

Strum355 · Strum355 · commit cc899cf6fed7 · 2020-11-30T17:33:37.000Z
diff --git a/docs/install.md b/docs/install.md
@@ -26,6 +26,8 @@ brew install cmake sourcegraph/brew/llvm@10 binutils
 
 # Installation
 
+Make sure to checkout any submodules, either with `git clone --recurse-submodules ...` or `git submodule update --init --recursive`
+
 ### Ubuntu
 
 ```sh
