Add sorce build suggestion

Author: LAbyOne

README.md

@@ -1,3 +1,4 @@
+
 # CloverBootloader
 Bootloader for macOS, Windows and Linux in UEFI and in legacy mode
 # Features
@@ -24,3 +25,14 @@ Bootloader for macOS, Windows and Linux in UEFI and in legacy mode
 - Create Clover boot entry in NVRAM with tool from GUI
 - Launch EFI command shell from GUI
 - Startup sound controlled by **F8** and checked by **F7**
+
+# Building from Source
+
+`mkdir -p $HOME/src && cd $HOME/src`
+
+`git clone -q https://github.com/CloverHackyColor/CloverBootloader`
+
+`cd CloverBootloader && git submodule update --init --recursive`
+
+`cd OpenCorePkg && git checkout master && git pull`
+#