Uopdating readme

README.md

@@ -1,28 +1,48 @@
-Waterfall
+# Waterfall
-=========
 
 Waterfall is a declarative task execution framework. 
-Why Another Execution Framework
+
-===============================
+# Why Another Execution Framework
 
 There are many, many execution frameworks out there that support defining
 tasks with inter-task dependencies. Most of them only partially include
 scheduling in their design.
 
-Overview
+# Building and Running
---------
 
-Resources
+```bash
-=========
+cargo build
+```
+
+# Overview
+
+## Example
+
+## Resources
 
 Resources are at the heart of Waterfall. They are simple things: labels
 with an associated set of time intervals. Tasks produce resources for
 given intervals.
 
-Tasks
+## Tasks
-=====
 
 Tasks are commands that run on a set schedule. Each task produces one or
 more `Resource`. The run schedule naturally breaks up the timeline into
-intervals. When a task runs at time $T_n$, it will make make each resource
+intervals. When a task runs at time `T_n`, it will make make each resource
-it provides available over the interval $(T_{n-1},T]$.
+it provides available over the interval `(T_{n-1},T]`.
+
+### Commands
+
+A task has three commands defined:
+
+- **check** - Command used to run an out-of-band verification of the data. Should have no side effects.
+- **up** - Command run to create resources.
+- **down** - Command run when removing resources.
+
+### Dependencies
+
+Tasks will run at their scheduled time (or immediately if their scheduled time
+has passed already).
+
+It's possible to define additional constraints on launching, though. Some tasks
+may need resources produced by other tasks before it can start.