Also treat some more mimetypes as text

lib/binary.py

@@ -25,18 +25,28 @@ BINARY = {
     ".zst",
 }
 
+TEXT_MIMETYPES = {
+    "message/rfc822",
+    "application/pgp-keys",
+    "application/x-gnupg-keyring",
+}
+
+
+def is_text_mimetype(mimetype):
+    if mimetype.startswith("text/"):
+        return True
+
+    return mimetype.split(";")[0] in TEXT_MIMETYPES
+
 
 def is_binary_or_large(filename, size):
     """Decide if is a binary file based on the extension or size"""
     binary_suffix = BINARY
     non_binary_suffix = {
-        ".1",
-        ".8",
         ".SUSE",
         ".asc",
         ".c",
         ".cabal",
-        ".cfg",
         ".changes",
         ".conf",
         ".desktop",