README.md lists available packages (#52)

Signed-off-by: Ziv Nevo <[email protected]>

README.md

@@ -1,5 +1,14 @@
 # models
-Models for connectivity and network resources
+A collection of Golang packages with models for connectivity and network resources
+
+## Packages
+* **interval** - A canonical representation of a set of intervals defined over integers
+* **ipblock** - A canonical representation of a set of IP ranges. Currently limited to IPv4
+* **hypercube** - A canonical representation of a set of n-dimensional hypercubes. All dimensions are defined over integers.
+* **netp** - Various structs for representing and handling common network protocols (TCP, UDP, ICMP)
+* **connection** - A canonical representation of a set of connections. E.g., for representing all protocols/ports/codes permitted by a given firewall, given a specific source and destination.
+* **spec** - A collection of structs for defining required connectivity. Automatically generated from a JSON schema (see below).
+
 ## Code generation
 `spec_schema.json` is the JSON schema for the input to VPC-synthesis. The data model in `pkg/spec` is auto-generated from this file using the below procedure.