Improve cgit detection

This can be tested on [kernel.org](https://git.kernel.org/cgit/)

src/apps.json

@@ -8575,7 +8575,13 @@
 			"cats": [
 				19
 			],
-			"html": "<[^>]+id='cgit'",
+			"meta": {
+				"generator": "^cgit v([\d.a-z-]+)$\\;version:\\1"
+			},
+			"html": [
+				"<[^>]+id='cgit'",
+				"generated by <a href='http://git.zx2c4.com/cgit/about/'>cgit v([\d.a-z-]+)</a>\\;version:\\1"
+			],
 			"icon": "cgit.png",
 			"implies": "Perl",
 			"website": "git.zx2c4.com/cgit"