Revert "F-Droid changelog"

This reverts commit da06910e9e.

app/build.gradle

@@ -399,8 +399,8 @@ preBuild.dependsOn copyMarkdown
 tasks.register('copyChangelog', Copy) {
     from "${rootDir}"
     into "../metadata/en-US/changelogs"
-    include "fdroid.txt"
-    rename "fdroid.txt", getVersionCode() + ".txt"
+    include "CHANGELOG.md"
+    rename "CHANGELOG.md", getVersionCode() + ".txt"
     filter { String line ->
         line
                 .replaceAll(".*Google Translate.*", "--------------------")

fdroid.txt

@@ -1 +0,0 @@
-Please see here for the changelog: https://github.com/M66B/FairEmail/blob/master/CHANGELOG.md