profiling: add documentation of lsprof 'sort' and 'nested'

mercurial/help/config.txt

@@ -990,6 +990,19 b' profiling is done using lsprof.'
     file exists, it is replaced. Default: None, data is printed on
     stderr
 
+``sort``
+    Sort field.  Specific to the ``ls`` instrumenting profiler.
+    One of ``callcount``, ``reccallcount``, ``totaltime`` and
+    ``inlinetime``.
+    Default: inlinetime.
+
+``nested``
+    Show at most this number of lines of drill-down info in a tree structure
+    after each main entry. This can help explain the difference between Total
+    and Inline.
+    Specific to the ``ls`` instrumenting profiler.
+    Default: 5.
+
 ``revsetalias``
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