Initial structure for lambda-builders repo

README.md

@@ -1,7 +1,26 @@
-## PRIVATE AWS Lambda Builders
+## Lambda Builders
 
-Helps you Build and Package AWS Lambda function code for 10+ runtimes & frameworks 
+Lambda Builders is a separate project that contains scripts to build Lambda functions, given a source location. It was
+built as part of SAM CLI `sam build` command.Read https://github.com/awslabs/aws-sam-cli/pull/743 for design document 
+explaining how Lambda Builders work in context of SAM CLI. 
 
-## License
+Eventually, we will move this library into a separate code repository so other tools can consume it. 
 
-This library is licensed under the Apache 2.0 License. 
+This project has certain attributes that make it unique:
+
+- Builders could be implemented in any programming language. Preferably in the language that they are building.
+- Some builders simply execute a binary (like Golang) without writing a Go script. We provide generic Python runner to implement 
+  such builders
+- We have one builder for each Programming Language + Framework combination. 
+
+
+### Scope of Builders
+
+- Each builder must have a CLI script that can be invoked directly from command line using the programming language
+  binary (ex: `python python-pip/cli.py` or `node nodejs-npm/cli.js`). The CLI interface speaks the JSON-RPC protocol.
+
+- Each builder also has a public module that can be directly imported in the language 
+  (ex: `from python-pip.rpc import builder`). This method takes same argument as the ones passed through JSON-RPC.
+  In fact, the CLI interface literally parses JSON-RPC and calls method. 
+
+