Better Chromium: support more folder paths

the `customizations` folder is a ubuntu concept (note that rpiOS chromium is derived from the original ubuntu chromium packaging). the folder name is defined in the chromium wrapper script as a function of the binary name. ubuntu packages chromium as `chromium-browser` however upstream chromium packaging refers to it as `chromium-browser-$channel` with channel being stable, beta, or unstable

apps/Better Chromium/install

@@ -18,8 +18,18 @@ elif [ -d /snap/chromium ] && [ -f /snap/bin/chromium ];then
   fi
   folder=/etc/chromium.d
 
-elif [ -d /etc/chromium-browser/customizations ];then
+elif [ -d /etc/chromium-browser ];then
+  sudo mkdir -p /etc/chromium-browser/customizations
   folder=/etc/chromium-browser/customizations
+elif [ -d /etc/chromium-browser-stable ];then
+  sudo mkdir -p /etc/chromium-browser-stable/customizations
+  folder=/etc/chromium-browser-stable/customizations
+elif [ -d /etc/chromium-browser-beta ];then
+  sudo mkdir -p /etc/chromium-browser-beta/customizations
+  folder=/etc/chromium-browser-beta/customizations
+elif [ -d /etc/chromium-browser-unstable ];then
+  sudo mkdir -p /etc/chromium-browser-unstable/customizations
+  folder=/etc/chromium-browser-unstable/customizations
 
 else
   error "User error: Cannot find the directory where Chromium keeps its flags! Usually this would be /etc/chromium.d or /etc/chromium-browser/customizations. On your system, neither of these directories exist. Please reach out to Botspot for this to be fixed."