Improve the learning pages for the VS Code extension

[nipunayf]

Description

The learn pages for the VS Code extension contain minor language issues and outdated information. Here are a few cases:

• The docs contain outdated screenshots.
  1. The Run code lens is no longer available for the tests; instead, it has been replaced with a green run icon containing all the options. link
  2. We can no longer run the program from the sequence diagram. https://github.com/ballerina-platform/ballerina-dev-website/issues/8975
• The mentioned shortcuts should not be unified to a single OS. Hence, for such cases, we should provide both types of shortcuts. link
• A document should be coherent when presenting information. For instance, in link, some sections present keyboard shortcuts, some explain how to right-click and navigate, and some do not contain this information at all. Again, inconsistencies exist in how we define commands here. In one instance, we describe quick access, while in another, we describe the action.
• There were cases in which proper spacing was not maintained between words, such as here.
• In some cases like this, incorrect words were used in the context.

Related issue(s) (optional)

https://github.com/ballerina-platform/ballerina-dev-website/issues/8975 https://github.com/ballerina-platform/ballerina-dev-website/issues/8973

[github-actions[bot]]

This issue is NOT closed with a proper Reason/ label. Make sure to add proper reason label before closing. Please add or leave a comment with the proper reason label now.

      - Reason/EngineeringMistake - The issue occurred due to a mistake made in the past.
      - Reason/Regression - The issue has introduced a regression.
      - Reason/MultipleComponentInteraction - Issue occured due to interactions in multiple components.
      - Reason/Complex - Issue occurred due to complex scenario.
      - Reason/Invalid - Issue is invalid.
      - Reason/Other - None of the above cases.