Document missing type flags as part of Stable ABI

The documentation is currently pretty inconsistent about listing the type flags as part of the Stable ABI. Some are listed and some aren't.
I've hopefully got all the important ones.

I haven't done `_Py_TPFLAGS_MATCH_SELF` which is exposed in the Limited API but starts with an underscore.

I also haven't done things like `Py_TPFLAGS_VALID_VERSION_TAG`, `Py_TPFLAGS_HAVE_FINALIZE`, `Py_TPFLAGS_HAVE_VERSION_TAG` which are exposed in the Limited API but now don't do anything.

Author: da-woods

Misc/stable_abi.toml

@@ -1786,6 +1786,28 @@
     added = '3.2'
 [const.Py_TPFLAGS_HAVE_GC]
     added = '3.2'
+[const.Py_TPFLAGS_READY]
+    added = '3.2'
+[const.Py_TPFLAGS_READYING]
+    added = '3.2'
+[const.Py_TPFLAGS_IS_ABSTRACT]
+    added = '3.2'
+[const.Py_TPFLAGS_LONG_SUBCLASS]
+    added = '3.2'
+[const.Py_TPFLAGS_LIST_SUBCLASS]
+    added = '3.2'
+[const.Py_TPFLAGS_TUPLE_SUBCLASS]
+    added = '3.2'
+[const.Py_TPFLAGS_BYTES_SUBCLASS]
+    added = '3.2'
+[const.Py_TPFLAGS_UNICODE_SUBCLASS]
+    added = '3.2'
+[const.Py_TPFLAGS_DICT_SUBCLASS]
+    added = '3.2'
+[const.Py_TPFLAGS_BASE_EXC_SUBCLASS]
+    added = '3.2'
+[const.Py_TPFLAGS_TYPE_SUBCLASS]
+    added = '3.2'
 
 [const.METH_VARARGS]
     added = '3.2'
@@ -2276,6 +2298,13 @@
 [function.PyGC_IsEnabled]
     added = '3.10'
 
+# New type flags in 3.10
+
+[const.Py_TPFLAGS_DISALLOW_INSTANTIATION]
+    added = '3.10'
+[const.Py_TPFLAGS_IMMUTABLETYPE]
+    added = '3.10'
+
 # Add new C API in Python 3.11
 
 [function.PyType_GetName]