docs: update README.md (#43)

* docs: update README.md

* docs: update README.md

README.md

-# Optimism Monorepo (VERY WIP)
+# <h1 align="center"> Optimism Monorepo </h1>
+
+**Monorepo implementing the Optimistic Ethereum protocol**
+
+![Github Actions](https://github.com/ethereum-optimism/optimism/workflows/typescript%20/%20contracts/badge.svg)
+![Github Actions](https://github.com/ethereum-optimism/optimism/workflows/integration/badge.svg)
+![Github Actions](https://github.com/ethereum-optimism/optimism/workflows/geth%20unit%20tests/badge.svg)
+
+## Documentation
+
+Extensive documentation is available [here](http://community.optimism.io/docs/)
+
+## Directory Structure
+
+* [`packages`](./packages): Contains all the typescript packages and contracts
+    * [`contracts`](./packages/contracts): Solidity smart contracts implementing the OVM
+    * [`core-utils`](./packages/core-utils): Low-level utilities and encoding packages
+    * [`hardhat-ovm`](./packages/hardhat-ovm): Hardhat plugin which enables the [OVM Compiler](https://github.com/ethereum-optimism/solidity)
+    * [`smock`](./packages/smock): Testing utility for mocking smart contract return values and storage
+    * [`data-transport-layer`](./packages/data-transport-layer): Event indexer, allowing the `l2geth` node to access L1 data
+    * [`batch-submitter`](./packages/batch-submitter): Daemon for submitting L2 transaction and state root batches to L1
+    * [`message-relayer`](./packages/message-relayer): Service for relaying L2 messages to L1
+* [`l2geth`](./l2geth): Fork of [go-ethereum v1.9.10](https://github.com/ethereum/go-ethereum/tree/v1.9.10) implementing the [OVM](https://research.paradigm.xyz/optimism#optimistic-geth).
+* [`integration-tests`](./integration-tests): Integration tests between a L1 testnet, `l2geth`,
+* [`ops`](./ops): Contains Dockerfiles for containerizing each service involved in the protocol, 
+as well as a docker-compose file for bringing up local testnets easily
 
 ## Quickstart
 
-```
+### Installation
+
+Dependency management is done using `yarn`. 
+
+```bash
 git clone git@github.com:ethereum-optimism/optimism.git
 cd optimism
 yarn
-yarn build # this is needed to generate the dist files locally
-yarn test
 ```
 
-If you get dependency errors: `git clean -fx && yarn clean && rm -rf node_modules/@eth-optimism/* && yarn install --force`
+After installing the dependencies, you must also build them so that the typescript
+is compiled down to javascript:
 
-## Taming the Monorepo
+```bash
+yarn build
+```
 
-1. You solely use yarn workspaces for the Mono-Repo workflow.
-1. You use lerna’s utility commands to optimize managing of multiple packages, e.g., selective execution of npm scripts for testing.
-1. You use lerna for publishing packages since lerna provides sophisticated features with its version and publish commands.
+### Unit tests
 
-## Incremental Tests
+All tests are run in parallel using `lerna`:
 
+```bash
+yarn test
 ```
-BRANCH_POINT="$(git merge-base $(git rev-parse --abbrev-ref HEAD) $(git describe origin/master))"
-changedPackages="$(npx lerna ls -p --since $BRANCH_POINT --include-dependents)"
+
+When you want to run tests only for packages that have changed since `master` (or any other branch)
+you can run `yarn lerna run test --parallel --since master`
+
+### Integration Tests
+
+The integration tests first require bringing up the Optimism stack. This is done via
+a Docker Compose network. For better performance, we also recommend enabling Docker 
+BuildKit
+
+```bash
+cd ops
+export COMPOSE_DOCKER_CLI_BUILD=1
+export DOCKER_BUILDKIT=1
+docker-compose build
+docker-compose up
 ```