docs: Stub new(er) auxlibs and auxprogs

Still need to actually be filled in.
Also rearranges auxlibs to be alphabetical order.

docs/source/appendix/auxprogs.rst

@@ -1,6 +1,8 @@
 Auxiliary programs
 ==================
 
+.. todo:: check this list is up to date and correct, esp yosys-smtbmc
+
 Besides the main yosys executable, the Yosys distribution contains a set of
 additional helper programs.
 
@@ -27,3 +29,11 @@ This is a fork of ABC with a small set of custom modifications that have not yet
 been accepted upstream. Not all versions of Yosys work with all versions of ABC.
 So Yosys comes with its own yosys-abc to avoid compatibility issues between the
 two.
+
+yosys-smtbmc
+------------
+
+yosys-witness
+-------------
+
+yosys-witness is a new tool to inspect and convert yosys witness traces.