update README (#23)

* update README

* update README

* update README

Author: Sid-Bhatia-0

README.md

@@ -1,44 +1,103 @@
 # RayCastWorlds
 
-**Important:** This package is not registered yet. It is a work in progress.
+This package provides simple first-person 3D games that can also be used as reinforcement learning environments. It is inspired by [DeepMind Lab](https://github.com/deepmind/lab).
 
-This package provides simple raycasted games.
+**Note:** This package is unregistered as of this writing and can be installed using the following command in the Julia REPL's `pkg` mode (enter `pkg` mode by pressing `]` after starting the REPL):
 
-Right now only one game is provided called `SingleRoom`.
+```
+add https://github.com/Sid-Bhatia-0/RayCastWorlds.jl
+```
+
+## Table of Contents
+
+* [Getting Started](#getting-started)
+* [Notes](#notes)
+
+[List of Environments](#list-of-environments)
+1. [SingleRoom](#singleroom)
+
+## Getting Started
+
+```julia
+import RayCastWorlds as RCW
+
+env = RCW.SingleRoomModule.SingleRoom()
+
+# reset the game. All environments are randomized
+
+RCW.reset!(env)
+
+# get names of actions that can be performed in this environment
+
+RCW.get_action_names(env)
+
+# perform actions in the environment
+
+RCW.act!(env, 1) # move forward
+RCW.act!(env, 2) # move backward
+RCW.act!(env, 3) # turn left
+RCW.act!(env, 4) # turn right
+
+# interactively play the game
+# keybindings:
+# `q`: quit
+# `r`: reset
+# `w`: move forward
+# `s`: move backward
+# `a`: turn left
+# `d`: turn right
+# `v`: toggle top view and camera view
+
+RCW.play!(env)
+
+# use the RLBase API
+
+import ReinforcementLearningBase as RLBase
+
+# wrap a game instance from this package to create an RLBase compatible environment
+
+rlbase_env = RCW.RLBaseEnv(env)
+
+# perform RLBase operations on the wrapped environment
+
+RLBase.reset!(rlbase_env)
+state = RLBase.state(rlbase_env)
+action_space = RLBase.action_space(rlbase_env)
+reward = RLBase.reward(rlbase_env)
+done = RLBase.is_terminated(rlbase_env)
+
+rlbase_env(1) # move forward
+rlbase_env(2) # move backward
+rlbase_env(3) # turn left
+rlbase_env(4) # turn right
+```
 
 ## Notes
 
-#### RayCaster
+### RayCaster
 
 The core raycasting algorithm is implemented in the [`RayCaster`](https://github.com/Sid-Bhatia-0/RayCaster.jl) package.
 
-#### Units
+### Units
 
-There are 4 types of units:
-1. 'wu': Stands for world units. These are usually floating point numbers representing positions in the real world.
-1. 'tu': Stands for tile units. These are integers representing positions on the tile map.
-1. 'pu': Stands for pixel units. These are integers representing positions on the visualization image.
-1. 'au': Stands for angle units. These are integers representing angles from 0 to `num_directions`.
+There are 4 types of units used throughout the code:
+1. `wu`: Stands for world units. These are usually floating point numbers representing positions in the real world.
+1. `tu`: Stands for tile units. These are integers representing positions on the tile map.
+1. `pu`: Stands for pixel units. These are integers representing positions on the visualization image.
+1. `au`: Stands for angle units. These are integers representing angles from 0 to `num_directions`.
 
-The height of the tile map correponds to the x-axis of the coordinate system (indexed with `i` in the code base) and width correponds to the y-axis (indexed with `j` in the code base) . This is to keep the coordinate system right handed.
+The height of the tile map correponds to the x-axis of the coordinate system (often indexed with `i`) and width correponds to the y-axis (often indexed with `j`). This keeps the coordinate system right-handed.
 
-#### Play
+## List of Environments
 
-Here is how you start the game:
+1. ### SingleRoom
 
-julia'''
-import RayCastWorlds as RCW
+    The objective of the agent is to navigate its way to the goal. When the agent tries to move into the goal tile, it receives a reward of 1 and the environment terminates.
 
-env = RCW.SingleRoomModule.SingleRoom()
+    Camera view:
 
-RCW.play!(env)
-'''
-
-Here are the keybindings:
-1. `q`: quit
-1. `r`: reset
-1. `w`: move forward
-1. `s`: move backward
-1. `a`: turn left
-1. `d`: turn right
-1. `v`: toggle top view and camera view
+    <img src="https://user-images.githubusercontent.com/32610387/128851560-4c713b0b-cf9f-4eed-bf60-439d456ab5f6.png">
+
+    Top view:
+
+    <img src="https://user-images.githubusercontent.com/32610387/128851489-befdb69e-157c-48ea-b6ac-7447e8018d93.png">