Retag 2.18.0 as 2.18.1

I accidentally built the .apk and uploaded it to Google Play before
doing a "git pull" or my main branch. So the 2.18.0 I uploaded to Google
Play was wrong. Because Google doesn't allow me to undo a release that
not a single person has installed yet, I'm retagging 2.18.0 as 2.18.1 to
keep it consistent on all platforms.

CHANGELOG.md

@@ -1,6 +1,6 @@
 # Changelog
 
-## v2.18.0 - 110
+## v2.18.1 - 111
 
 - Arabic language support
 - Display archived card count in group overview

app/build.gradle

@@ -18,8 +18,8 @@ android {
         applicationId "me.hackerchick.catima"
         minSdkVersion 21
         targetSdkVersion 31
-        versionCode 110
-        versionName "2.18.0"
+        versionCode 111
+        versionName "2.18.1"
 
         vectorDrawables.useSupportLibrary true
         multiDexEnabled true