Add reference documentation about the tree matcher (TreePattern).

doc/reference/index.rst

@@ -13,3 +13,4 @@ Reference Guide
    reference_taxonomy
    reference_smartview
    reference_treeview
+   reference_treematcher

doc/reference/reference_treematcher.rst

@@ -0,0 +1,7 @@
+Tree matcher
+============
+
+.. automodule:: ete4.treematcher.treematcher
+   :members:
+   :undoc-members:
+   :special-members: __init__

ete4/treematcher/treematcher.py

@@ -18,6 +18,16 @@ class TreePattern(Tree):
     """
 
     def __init__(self, pattern='', children=None, parser=1, safer=False):
+        """
+        :param pattern: Tree pattern to match, as a newick string. Optionally
+            with conditions on the nodes too (in place of node names).
+        :param safer: If True, calls to eval() will be safer by strongly
+            restricting the Python keywords that can be used.
+
+        The other parameters (children and parser) are needed to call
+        Tree's constructor appropriately, but should not be used when
+        creating a TreePattern.
+        """
         if type(pattern) == str:
             # We expect a newick tree whose names will be the conditions
             # to check for in each node. No need to end with ";".