Update and expand public suffix list's attribution information

Say where the git repo is, for finding commit IDs, but make clear that
the download should come from the public site.  Revised Description to
the closest match to it I could find on the current web-site (on the
home page).  Mention where the script to convert the data live.

Task-number: QTBUG-72623
Change-Id: Ie5f7b2b0c21cdf1c24e311c13866cb1bb02e6973
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>

src/corelib/io/qt_attribution.json

@@ -2,7 +2,7 @@
     "Id": "psl",
     "Name": "The Public Suffix List",
     "QDocModule": "qtcore",
-    "Description": "The Public Suffix List is an initiative of the Mozilla Project,
+    "Description": "The Public Suffix List is an initiative of Mozilla,
 but is maintained as a community resource. It is available for use in any software,
 but was originally created to meet the needs of browser manufacturers.
 It allows browsers to, for example:
@@ -14,9 +14,11 @@ It allows browsers to, for example:
 - Accurately sort history entries by site",
 
     "Files": "qurltlds_p.h",
-    "QtUsage": "Used in Qt Core to avoid \"supercookies\" being set in the cookie jar
+    "QtUsage": "See util/corelib/qurl-generateTLDs/ for code-generator",
+    "QtUsage": "Used in Qt Core to avoid setting \"supercookies\" in the cookie jar
 supported by Qt (by the QNetworkCookieJar class).",
 
+    "Homepage": "Consult https://github.com/publicsuffix/list for the sha1 but download from ...",
     "Homepage": "http://publicsuffix.org/",
     "Version": "Generated on 2018-01-04",
     "License": "Mozilla Public License 2.0",