Add "Advanced usage" to readme

[filipopo]

"Fixes" #337

[umihico]

Thank you for the contribution! I have several suggestions to improve the documentation:

1. Missing rebuild instructions

The current example shows changing the code and then running the container, but it's missing the rebuild step:

• To get more than a minimal example, change the code and then run the container

• To get more than a minimal example, change the code, rebuild the image, and then run the container

You should add the rebuild command before running:
docker build -t my-selenium-lambda .
docker run --name selenium-lambda-demo -p 9000:8080 my-selenium-lambda

2. Add language specifiers to code blocks

All code blocks should have language specifiers for proper syntax highlighting:

• Shell commands: ```bash
• Python code: ```python

3. Use permalink for code reference

Instead of:
Change https://github.com/umihico/docker-selenium-lambda/blob/main/main.py#L25

Use a permalink to a specific commit to prevent broken links when the file changes:
Change https://github.com/umihico/docker-selenium-lambda/blob/7a19acc/main.py#L25

4. Container naming

The container name "demo" is too generic. Consider using something more specific like:

• selenium-lambda-demo
• aws-lambda-selenium-demo

5. Serverless framework example verification

Has the serverless framework example been tested?
sls invoke --function demo --data '{"url": "https://github.com"}'
Please confirm this works with the current setup.

[filipopo]

Done but regarding 5. I must admit, I never used sls in my life😅I tested everything else though. Maybe you can test it or I'll try doing it later

[umihico]

Then please just remove the step. Unconfirmed commands should never be on the README..

BTW, did you confirm others?

[filipopo]

I had a small typo because my intention in #337 was to put "target" in the event, otherwise everything works 💪

[filipopo]

Is there anything else that you'd like to change @umihico ?