Add notes on techtree.json

docs/index.rst

@@ -13,8 +13,6 @@ If you are looking for something specific, you can either check the
 If you want to know about a certain topic, check the table of contents below
 this paragraph.
 
-.. TODO: Add information about tree.json
-
 .. TODO: Base repos for C++ AI
 
 Table of contents

docs/perception.rst

@@ -65,12 +65,20 @@ TechTree
    build a certain unit and what builds it. It only has one method, which is
    used to look-up unit types properties:
 
+   This class has some invalid information by default, this can be corrected by
+   placing the file `techtree.json` in the working directory. The
+   `techtree.json` files are available here_, select the lastest version. A
+   recent file is included in the `template repository`_.
+
    .. method:: get_data(argument) -> library.TypeData
 
       Argument is either an instance of the class :class:`library.UnitType` or
       an instance of the class :class:`library.CCUpgrade`, depending on what
       information is wanted.
 
+.. _here: https://github.com/noorus/sc2-gamedata
+.. _`template repository`: https://gitlab.ida.liu.se/starcraft-api/sc2-python-bot
+
 TypeData
 ~~~~~~~~