bpo-32159: Revert Misc/svnmap.txt (#4639)
Partially revert the commit fe2d5babba5d26de2093b6518316b268488187be.
Clarify the usage of this file in Misc/README.
diff --git a/Misc/README b/Misc/README
index 0d26c3c..8e8acbc 100644
--- a/Misc/README
+++ b/Misc/README
@@ -22,5 +22,7 @@
README.coverity Information about running Coverity's Prevent on Python
README.valgrind Information for Valgrind users, see valgrind-python.supp
SpecialBuilds.txt Describes extra symbols you can set for debug builds
+svnmap.txt Map of old SVN revs and branches to hg changeset ids,
+ help history-digging
valgrind-python.supp Valgrind suppression file, see README.valgrind
vgrindefs Python configuration for vgrind (a generic pretty printer)