Set up ESLint for post service

[aserputov]

Issue This PR Addresses

Fixes #3157

Type of Change

• Bugfix: Change which fixes an issue
• New Feature: Change which adds functionality
• Documentation Update: Change which improves documentation
• UI: Change which improves UI

Description

Steps to test the PR

Checklist

• Quality: This PR builds and passes our npm test and works locally
• Tests: This PR includes thorough tests or an explanation of why it does not
• Screenshots: This PR includes screenshots or GIFs of the changes made or an explanation of why it does not (if applicable)
• Documentation: This PR includes updated/added documentation to user exposed functionality or configuration variables are added/changed or an explanation of why it does not(if applicable)

[gitpod-io]

[RC-Lee]

Make sure to rebase and resolve conflicts first please. Thanks!

[aserputov]

@cindyledev while working on this issue, I discovered that there is a bug if we use @senecacdot/eslint-config-telescope": "1.0.0". At first, I thought that problem was with rules in .eslint. The bug:

[Definition for rule '@typescript-eslint/no-shadow' was not found](https://stackoverflow.com/questions/66033302/definition-for-rule-typescript-eslint-no-shadow-was-not-found 

To fix it, I changed all of the dependencies to 1.0.0. This bug appeared after I rebased.

[cindyorangis]

According to #3247, we have chosen to unlink local packages so any eslint-config-telescope shouldn't be using workspace:1.0.0. It should be 1.0.0 instead

[aserputov]

@cindyledev 1:1 error Definition for rule '@typescript-eslint/no-shadow' was not found @typescript-eslint/no-shadow. Do you have any guess, why this can be? I think it's not only on my side.

[cindyorangis]

We just updated eslint-config-telescope to v1.1.0 in #3267 and many of the eslint configurations were refactored in #3253. To pick up the latest updates which addresses the no-shadow error, change the 1.0.0 to 1.1.0