Add examples to run k6 tests in CI using github actions

[DefCon-007]

• Add a table of contents in the readme to highlight all the sections
• Add examples for running k6 test in CI using GitHub actions

[DefCon-007]

Adding this small table of contents to show various sections of the readme easily

[ppcano]

lgtm, but i haven't tested. If you want me to test it locally with act, please, tell me.

[ppcano]

@DefCon-007 ,got an error when running it with act:

act -W .github/workflows/example_basic_test.yaml 

....
[Basic Test Workflow/k6 test run - basic example]   🐳  docker exec cmd=[node /var/run/act/actions/grafana-run-k6-action@v1/dist/index.js] user= workdir=
| /run/act/actions/grafana-run-k6-action@v1/dist/index.js:212
|         throw new Error(`Input required and not supplied: ${name}`);
|         ^
| 
| Error: Input required and not supplied: github-token
|     at Object.getInput (/run/act/actions/grafana-run-k6-action@v1/dist/index.js:212:15)
|     at 2179 (/run/act/actions/grafana-run-k6-action@v1/dist/index.js:34175:20)

[DefCon-007]

lgtm, but i haven't tested. If you want me to test it locally with act, please, tell me.

I tested them on my fork here - https://github.com/DefCon-007/quickpizza/actions

got an error when running it with act

The github-token is present by default when running workflow in github actions. I will try and see how we can run them via act as well