auto-clean newlines and spaces in repo/archive descriptions

This gives us flexibility in how the blocks of text can be formatted in
config.py, but also provides a more useful format for displaying since the
client can decide where to wrap the text.

examples/config.py

@@ -33,11 +33,12 @@ repo_maxage = 0
 repo_url = "https://MyFirstFDroidRepo.org/fdroid/repo"
 repo_name = "My First FDroid Repo Demo"
 repo_icon = "fdroid-icon.png"
-repo_description = (
-    "This is a repository of apps to be used with FDroid. Applications in this "
-    + "repository are either official binaries built by the original application "
-    + "developers, or are binaries built from source by the admin of f-droid.org "
-    + "using the tools on https://gitlab.com/u/fdroid.")
+repo_description = """
+This is a repository of apps to be used with FDroid. Applications in this
+repository are either official binaries built by the original application
+developers, or are binaries built from source by the admin of f-droid.org
+using the tools on https://gitlab.com/u/fdroid.
+"""
 
 # As above, but for the archive repo.
 # archive_older sets the number of versions kept in the main repo, with all
@@ -47,9 +48,9 @@ archive_older = 3
 archive_url = "https://f-droid.org/archive"
 archive_name = "My First FDroid Archive Demo"
 archive_icon = "fdroid-icon.png"
-archive_description = (
-    "The repository of older versions of applications from the main demo "
-    + "repository.")
+archive_description = """
+The repository of older versions of applications from the main demo repository.
+"""
 
 
 # The ID of a GPG key for making detached signatures for apks. Optional.