add a few clarifications to contributing page (#28)

docs/contributing.md

@@ -21,14 +21,17 @@ The following is a brief overview of the internal code structure
 ```
 ## Development
 
-For non-linux users, we have a [vagrant](https://learn.hashicorp.com/tutorials/vagrant/getting-started-install) box available. Just run
+For non-Linux users, we have a [Vagrant](https://learn.hashicorp.com/tutorials/vagrant/getting-started-install) box available for you to easily get started with a Linux environment. 
+
+After checking out the source code of the bumblebee repo, you can simply start the Vagrant VM and SSH into the VM:
 
 ```bash
+cd bumblebee
 vagrant up
 vagrant ssh
 ```
 
-This folder will be mounted under "/source" in the vagrant VM.
+This bumblebee folder will be mounted under "/source" in the vagrant VM. This VM has [BTF](https://www.kernel.org/doc/html/latest/bpf/btf.html) already enabled, along with all other required tool chains such as Docker, Go, LLVM, etc. Refer to its [Vagrantfile](/Vagrantfile) for more details.
 
 For fast iterations of go code / bpf programs, you can build with our build script, and run with go run as follows:
 
@@ -38,14 +41,20 @@ cd /source
 go run -exec sudo ./bee/main.go run tcpconnect.o
 ```
 
-To make a local docker image for the bee to use, you can run
+To make a local docker image for the `bee` to use, you can run:
 
 ```bash
 make docker-build
 ```
 
-or, if for podman:
+Or, if for podman:
 
 ```bash
 make docker-build DOCKER=podman
-```
+```
+
+You can then use the docker image in the `bee build` command, for example:
+
+```bash
+bee build examples/tcpconnect/tcpconnect.c tcpconnect.o -i $DOCKER_BUILT_IMAGE
+```