More VSCode devcontainer improvements

[agners]

What does this implement/fix?

Quick description and explanation of changes

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Other

Related issue or feature (if applicable): fixes

Pull request in esphome-docs with documentation (if applicable): esphome/esphome-docs#

Test Environment

• ESP32
• ESP8266

Example entry for config.yaml:

# Example config.yaml

Checklist:

• The code change is tested and works locally.
• Tests have been added to verify that the new code works (under tests/ folder).

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated in esphome-docs.

[agners]

@dentra maybe you can have a look at this changes.

[jesserockz]

Nice!

[dentra]

@dentra maybe you can have a look at this changes.

looks great!

additionally at my opinion it would be nice to add running script/quicktest

[OttoWinter]

additionally at my opinion it would be nice to add running script/quicktest

yeah some of the helper scripts would be good too - but we can add those later