doc: simple offsets with generic syntax

same as original fix for the Core
fix footer into a single line and add UTC alias notice

code/scripts/tzdata.py

@@ -2,8 +2,31 @@ import argparse
 import mmap
 import os
 import pytz
+import re
 import sys
 
+def maybe_fix_value(value):
+    return re.sub(r"<[^>]*>", "UNK", value)
+
+
+def maybe_skip_zone(zone):
+    return zone.startswith("Etc/") or zone in ("GB-Eire", "W-SU")
+
+
+def utc_alias(zone):
+    return zone in (
+        "Universal",
+        "UTC",
+        "UCT",
+        "Zulu",
+        "GMT",
+        "GMT+0",
+        "GMT-0",
+        "GMT0",
+        "Greenwich",
+    )
+
+
 def zones(root):
     out = []
 
@@ -14,7 +37,7 @@ def zones(root):
                 continue
 
             m = mmap.mmap(f.fileno(), 0, prot=mmap.PROT_READ)
-            newline = m.rfind(b'\n', 0, len(m) - 1)
+            newline = m.rfind(b"\n", 0, len(m) - 1)
             if newline < 0:
                 continue
 
@@ -26,21 +49,46 @@ def zones(root):
     out.sort(key=lambda x: x[0])
     return out
 
+
 def table(zones):
+    utcs = []
+    rows = []
+
+    for name, value in zones:
+        if utc_alias(name):
+            utcs.append(name)
+            continue
+
+        if maybe_skip_zone(name):
+            continue
+
+        rows.append(f"|{name}|{maybe_fix_value(value)}|")
+
     print("|Name|Value|")
     print("|---|---|")
-    for name, value in zones:
-        print(f"|{name}|{value}|")
+    for name in utcs:
+        print(f"|{name}|UTC0|")
 
+    last = ""
+    for row in rows:
+        prefix, _, _ = row.partition("/")
+        if last != prefix:
+            last = prefix
+            print("|||")
+        print(row)
+    print()
+    print("---")
     print()
-    print(f"*{pytz.OLSON_VERSION=}*")
-    print(f"*{pytz.VERSION=}*")
+    print(f"Generated with *{pytz.OLSON_VERSION=} {pytz.VERSION=}*")
+
 
 if __name__ == "__main__":
     parser = argparse.ArgumentParser()
-    parser.add_argument("--root",
+    parser.add_argument(
+        "--root",
         help="Where do we get raw zoneinfo files from",
-        default=os.path.join(os.path.dirname(pytz.__file__), "zoneinfo"))
+        default=os.path.join(os.path.dirname(pytz.__file__), "zoneinfo"),
+    )
     args = parser.parse_args()
 
     table(zones(args.root))