docs: Update installing and getting started guides (#16)

Resolves: #24

Co-authored-by: Liz Rice <liz@lizrice.com>
Signed-off-by: Daniel Pacak <pacak.daniel@gmail.com>

CONTRIBUTING.md

@@ -0,0 +1,3 @@
+# Contributing
+
+TODO

HACKING.md

@@ -0,0 +1,135 @@
+# Hacking
+
+## Prerequisites
+
+- [Go 1.14 or above](https://golang.org/dl/)
+
+## Getting Started
+
+```
+$ git clone git@github.com:aquasecurity/starboard.git
+$ cd starboard
+$ make build
+$ ./bin/starboard help
+```
+
+## Testing
+
+We generally require tests to be added for all but the most trivial of changes. You can run the tests using the
+command below:
+
+```
+$ make test
+```
+
+## Generating Code
+
+Code generators are used a lot in the implementation of native Kubernetes resources, and we're using the very same
+generators here for custom security resources. This project follows the patterns of
+[k8s.io/sample-controller][k8s-sample-controller], which is a blueprint for many controllers built in Kubernetes itself.
+
+The code generation starts with:
+
+```
+$ go mod vendor
+$ export GOPATH="$(go env GOPATH)"
+$ ./hack/update-codegen.sh
+```
+
+In addition, there is a second script called `./hack/verify-codegen.sh`. This script calls the
+`./hack/update-codegen.sh` script and checks whether anything changed, and then it terminates with a nonzero return
+code if any of the generated files is not up-to-date. We're running it as a step in the CI/CD pipeline.
+
+## Using Generated Code
+
+An instance of a client set can be created with the `NewForConfig` helper function. This is analogous to the client sets
+for core Kubernetes resources. The following listings shows how to create an instance of the
+`vulnerabilities.aquasecurity.github.io` resource and send it to the Kubernetes API.
+
+```go
+package main
+
+import (
+	"log"
+	"os"
+	"time"
+
+	"k8s.io/client-go/tools/clientcmd"
+
+	starboard "github.com/aquasecurity/starboard/pkg/apis/aquasecurity/v1alpha1"
+	starboardapi "github.com/aquasecurity/starboard/pkg/generated/clientset/versioned"
+	meta "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+func main() {
+	if err := run(os.Args); err != nil {
+		log.Fatalf("Error: %v", err)
+	}
+}
+
+func run(_ []string) (err error) {
+	config, err := clientcmd.BuildConfigFromFlags("", "~/.kube/config")
+	if err != nil {
+		return
+	}
+	client, err := starboardapi.NewForConfig(config)
+	if err != nil {
+		return
+	}
+
+	vulnerability := &starboard.Vulnerability{
+		ObjectMeta: meta.ObjectMeta{
+			Name:      "a2a6b603-97b4-4e5d-bbcd-404723c4177a",
+			Namespace: "dev",
+			Labels: map[string]string{
+				"starboard.resource.kind":  "Deployment",
+				"starboard.resource.name":  "nginx",
+				"starboard.container.name": "nginx",
+			},
+			Annotations: map[string]string{
+				"starboard.history.limit": "10",
+				"starboard.image.digest":  "sha256:72c42ed48c3a2db31b7dafe17d275b634664a708d901ec9fd57b1529280f01fb",
+			},
+		},
+		Report: starboard.VulnerabilityReport{
+			Scanner: starboard.Scanner{
+				Name:    "Trivy",
+				Vendor:  "Aqua Security",
+				Version: "latest",
+			},
+			Artifact: starboard.Artifact{
+				Repository: "library/nginx",
+				Digest:     "sha256:72c42ed48c3a2db31b7dafe17d275b634664a708d901ec9fd57b1529280f01fb",
+				Tag:        "1.16",
+				MimeType:   "application/vnd.docker.distribution.manifest.v2+json",
+			},
+			Summary: starboard.VulnerabilitySummary{
+				CriticalCount: 0,
+				HighCount:     0,
+				MediumCount:   1,
+				LowCount:      0,
+				UnknownCount:  0,
+			},
+			Vulnerabilities: []starboard.VulnerabilityItem{
+				{
+					VulnerabilityID:  "CVE-2019-1549",
+					Resource:         "openssl",
+					Severity:         starboard.SeverityMedium,
+					InstalledVersion: "1.1.1c-r0",
+					FixedVersion:     "1.1.1d-r0",
+					Title:            "openssl: information disclosure in fork()",
+				},
+			},
+		},
+	}
+
+	_, err = client.AquasecurityV1alpha1().
+		Vulnerabilities("dev").
+		Create(vulnerability)
+	return
+}
+```
+
+Note that higher-level tools like informers and listers are also generated and available.
+
+[k8s-sample-controller]: https://github.com/kubernetes/sample-controller