[PATCH 10 of 10 V2] discovery: improve partial discovery documentation

[Boris Feld]

# HG changeset patch
# User Boris Feld <boris.feld at octobus.net>
# Date 1546620858 -3600
#      Fri Jan 04 17:54:18 2019 +0100
# Node ID fa34f71579ebe2ea7e530e514109938913d5c3c2
# Parent  81d3ec14b6b84ab16df6fd8e9de24a8c2f81e011
# EXP-Topic discovery-refactor
# Available At https://bitbucket.org/octobus/mercurial-devel/
#              hg pull https://bitbucket.org/octobus/mercurial-devel/ -r fa34f71579eb
discovery: improve partial discovery documentation

The older documentation could be improved.

diff --git a/mercurial/setdiscovery.py b/mercurial/setdiscovery.py
--- a/mercurial/setdiscovery.py
+++ b/mercurial/setdiscovery.py
@@ -167,9 +167,10 @@ class partialdiscovery(object):
     Feed with data from the remote repository, this object keep track of the
     current set of changeset in various states:
 
-    - common:    own nodes I know we both know
-    - undecided: own nodes where I don't know if remote knows them
-    - missing:   own nodes I know remote lacks
+    - common:    revs also known remotely
+    - undecided: revs we don't have information on yet
+    - missing:   revs missing remotely
+    (all tracked revisions are known locally)
     """
 
     def __init__(self, repo, targetheads):