docs: add build from source guide (#32)

docs/guide/readme.md

@@ -1,27 +1,78 @@
 # Quick start
 
-
 ## Using Docker
 
-* Install [docker] and [docker-compose].
-* Grab Pomerium's included example [`docker-compose.yml`](https://raw.githubusercontent.com/pomerium/pomerium/master/docker-compose.yml) directly or by cloning the repository.
-* Update `docker-compose.yml` to match your [identity provider] settings. 
-* Copy your subdomain's wild-card TLS certificate next to the compose file. If you don't have one handy, the included [script] generates one from [LetsEncrypt].
-* Run docker-compose by runnig the command `$ docker-compose up`. 
-* Pomerium is configured to delegate access to two test apps [helloworld] and [httpbin]. Navigate to `hello.corp.example.com` or `httpbin.corp.example.com`. You should see something like the following in your browser and in your terminal. 
+- Install [docker] and [docker-compose].
+- Grab Pomerium's included example [`docker-compose.yml`](https://raw.githubusercontent.com/pomerium/pomerium/master/docker-compose.yml) directly or by cloning the repository.
+- Update `docker-compose.yml` to match your [identity provider] settings.
+- Copy your subdomain's wild-card TLS certificate next to the compose file. If you don't have one handy, the included [script] generates one from [LetsEncrypt].
+- Run docker-compose by runnig the command `$ docker-compose up`.
+- Pomerium is configured to delegate access to two test apps [helloworld] and [httpbin]. Navigate to `hello.corp.example.com` or `httpbin.corp.example.com`. You should see something like the following in your browser and in your terminal.
 
 ![Getting started](./get-started.gif)
 
 [![asciicast](https://asciinema.org/a/tfbSWkUZgMRxHAQDqmcjjNwUg.svg)](https://asciinema.org/a/tfbSWkUZgMRxHAQDqmcjjNwUg)
 
-[docker-compose]: (https://docs.docker.com/compose/install/)
-[docker]: https://docs.docker.com/install/
-[download]: https://github.com/pomerium/pomerium/releases
-[kms]: https://en.wikipedia.org/wiki/Key_management
+## From source
+
+### Get the code
+
+Using [git](https://git-scm.com/), retrieve the latest copy of pomerium's source code by cloning the repository.
+
+```bash
+# where `$HOME/pomerium` is the directory you want to save pomerium
+git clone https://github.com/pomerium/pomerium.git $HOME/pomerium
+```
+
+Build pomerium from source in a single step using make.
+
+```bash
+cd $HOME/pomerium
+make
+```
+
+The command will run all the tests, some code linters, then build the binary. If all is good, you should now have a freshly built pomerium binary in the `pomerium/bin` directory.
+
+### Configure
+
+Make a copy of the [env.example] and name it something like `env`.
+
+```bash
+cp env.example env
+```
+
+Modify your `env` configuration to to match your [identity provider] settings.
+
+```bash
+vim env
+```
+
+### Run
+
+Finally, source the the configuration `env` file and run pomerium.
+
+```bash
+source ./env
+./bin/pomerium
+```
+
+### All-in-one
+
+Assuming your configuration file ready to go, you can simply use this one-liner.
+
+```bash
+make && source ./env && ./bin/pomerium
+```
+
 [certbot]: https://certbot.eff.org/docs/install.html
-[script]: https://github.com/pomerium/pomerium/blob/master/scripts/generate_wildcard_cert.sh
-[source]: https://github.com/pomerium/pomerium#start-developing
-[identity provider]: ./identity-providers.md
+[docker]: https://docs.docker.com/install/
+[docker-compose]: (https://docs.docker.com/compose/install/)
+[download]: https://github.com/pomerium/pomerium/releases
+[env.example]: https://github.com/pomerium/pomerium/blob/master/env.example
 [helloworld]: https://hub.docker.com/r/tutum/hello-world
 [httpbin]: https://httpbin.org/
-[LetsEncrypt]: https://letsencrypt.org/
+[identity provider]: ./identity-providers.md
+[kms]: https://en.wikipedia.org/wiki/Key_management
+[letsencrypt]: https://letsencrypt.org/
+[script]: https://github.com/pomerium/pomerium/blob/master/scripts/generate_wildcard_cert.sh
+[source]: https://github.com/pomerium/pomerium#start-developing