change min Thunderbird version to 91.0a1

README.md

@@ -1,6 +1,8 @@
 # Spam Scores (Thunderbird Add-on)
 
-Spam Scores is an add-on for Thunderbird (Version 78.0a1 - \*). It can display spam scores according to mail headers. The add-on supports spam/ham score headers of Rspamd, SpamAssassin and MailScanner. It adds a column with the overall spam score to the mail list view and shows details of any matched spam/ham rule.
+Spam Scores is an add-on for Thunderbird (Version 91.0a1 - \*). For Thunderbird 78.* the last working version of this add-on is [1.3.1](https://github.com/friedPotat0/Spam-Scores/releases/tag/1.3.1).
+
+The add-on can display spam scores according to mail headers. The add-on supports spam/ham score headers of Rspamd, SpamAssassin and MailScanner. It adds a column with the overall spam score to the mail list view and shows details of any matched spam/ham rule.
 
 > :warning: The add-on needs mails with headers like "X-Spamd-Result", "X-Spam-Report", "X-Rspamd-Report/-Score", "X-SpamCheck", "X-Spam-Status" or "X-VR-SPAMSCORE" to work. If a mail does not have one of these headers, it cannot display any spam score. Please make sure to check your mails for these headers before creating an issue. The add-on does not currently support spam headers from GMX, as these have a different score scale.
 

manifest.json

@@ -8,8 +8,8 @@
   "applications": {
     "gecko": {
       "id": "spamscores@czaenker",
-      "strict_min_version": "78.0a1",
-      "strict_max_version": "91.*"
+      "strict_min_version": "91.0a1",
+      "strict_max_version": "*"
     }
   },
   "icons": {