Add custom changes functionality to update.bash

Fixes #97

Signed-off-by: Ethan Dye <mrtops03@gmail.com>

README.md

@@ -71,6 +71,12 @@ Note that this sync service is not installed by default, you must install it sep
 sudo /path/to/zram-config/update.bash
 ```
 
+To make changes to the code or checkout a specific branch/tag and prevent it from updating/resetting all changes run the following instead.
+
+``` shell
+sudo /path/to/zram-config/update.bash custom
+```
+
 ### Uninstall
 
 ``` shell

update.bash

@@ -27,11 +27,13 @@ if [[ $OS == "ubuntu" ]] && [[ $(bc -l <<< "$(grep -o '^VERSION_ID=.*$' /etc/os-
   fi
 fi
 
-git -C "$BASEDIR" fetch origin
-git -C "$BASEDIR" fetch --tags --force --prune
-git -C "$BASEDIR" clean --force -x -d
-git -C "$BASEDIR" checkout main
-git -C "$BASEDIR" reset --hard origin/main
+if [[ $1 != "custom" ]]; then
+  git -C "$BASEDIR" fetch origin
+  git -C "$BASEDIR" fetch --tags --force --prune
+  git -C "$BASEDIR" clean --force -x -d
+  git -C "$BASEDIR" checkout main
+  git -C "$BASEDIR" reset --hard origin/main
+fi
 
 make --always-make --directory="${BASEDIR}/overlayfs-tools"