Updated titles

docs/source/input_api.rst

@@ -1,8 +1,8 @@
 .. _api:
 
-***************************
+************************************
-Model building - Python API
+Advanced Model Building (Python API)
-***************************
+************************************
 
 Introduction
 ============

docs/source/input_hash_cmds.rst

@@ -1,7 +1,7 @@
 .. _commands:
 
 ******************************
-Model building - hash commands
+Model building (hash commands)
 ******************************
 
 An input file has to be supplied to gprMax which should contain all the necessary information to run a GPR model. The input file is an ASCII text file which can be prepared with any text editor or word-processing program. In the input file the hash character (``#``) is reserved and is used to denote the beginning of a command which will be passed to gprMax. The general syntax of commands is:

docs/source/output.rst

@@ -1,8 +1,8 @@
 .. _output:
 
-*************
+*****************
-Model outputs
+Simulation Output
-*************
+*****************
 
 Field(s) output
 ===============