commands: removed part of description from abort and continue

The description for registration of new `continuefunc` or `abortfunc`
is removed as it is not required from user perspective.

Differential Revision: https://phab.mercurial-scm.org/D6660

mercurial/commands.py

@@ -141,8 +141,6 b' def abort(ui, repo, **opts):'
     and unshelve if they are in an unfinished state.
 
     use --dry-run/-n to dry run the command.
-    A new operation can be added to this by registering the operation and
-    abort logic in the unfinishedstates list under statemod.
     """
     dryrun = opts.get(r'dry_run')
     abortstate = cmdutil.getunfinishedstate(repo)
@@ -1903,8 +1901,6 b' def continuecmd(ui, repo, **opts):'
     and unshelve if they are in an interrupted state.
 
     use --dry-run/-n to dry run the command.
-    A new operation can be added to this by registering the operation and
-    continue logic in the unfinishedstates list under statemod.
     """
     dryrun = opts.get(r'dry_run')
     contstate = cmdutil.getunfinishedstate(repo)