dirstate-tracked-key: update the config value to match latest discussion
Special cases are not special enough, we align the option name on the other.
The `version` value is undocumented for now as it can only have a single value.
It is supported in the code to properly detect and abort if more value are
introduced in the future value.
Differential Revision: https://phab.mercurial-scm.org/D12184
cat >> $HGRCPATH <<EOF
[extensions]
narrow=
[experimental]
changegroup3 = True
EOF