doc/tutorial/basics: various improvements

- added section for templates
- updated ambiguity in bottom.md
- several small fixes

Change-Id: Iac03e7b99eec1ea352cb30d815a8cfbfb6896b18
diff --git a/doc/tutorial/basics/foldany.md b/doc/tutorial/basics/foldany.md
index 1bcab41..b933eb2 100644
--- a/doc/tutorial/basics/foldany.md
+++ b/doc/tutorial/basics/foldany.md
@@ -6,7 +6,7 @@
 
 This also works if a struct has more than one member.
 
-In general, any JSON configuration can be expressed as a collection of
+In general, any JSON object can be expressed as a collection of
 path-leaf pairs without using any curly braces.
 
 <!-- CUE editor -->