Update Concept.md to incorporate k8s document style guidelines 📖
Update Concept.md to incorporate k8s document style guidelines 📖

Guidelines are available here : https://kubernetes.io/docs/contribute/style/style-guide/
Guidelines applied here:
- Use present tense.
- Use active voice.
- Use simple and direct language
- Use camel case for API objects
- Avoid using "we"

Signed-off-by: Vincent Demeester <b98c0fd48a8945096c766de790fe70420dd2f223@redhat.com>

tektoncd/pipeline,tektoncd/pipeline