Migrate FabricBot Tasks to Config-as-Code` (#356)

**TL;DR;** Requesting to add [FabricBot](https://eng.ms/docs/products/1es-data-insights/merlinbot/extensions/fabricbot_overview) configuration associated with your repository to `.github/fabricbot.json`.

**Context**

FabricBot is now a [config-as-code-only](https://eng.ms/docs/products/1es-data-insights/merlinbot/extensions/bot-config-as-code) platform. As a result, while you can still use the [FabricBot Configuration Portal](https://portal.fabricbot.ms/bot/?repo=microsoft/PowerShellForGitHub) to modify your FabricBot configuration, you can no longer save the changes. The only way to save changes to your configuration at the moment is to _export configuration_ from the portal and upload the exported configuration to `.github/fabricbot.json` in your repository. In this pull request, we are adding your FabricBot configuration to your repository at `.github/fabricbot.json` so that you can make changes to it going forward.

While the [FabricBot Configuration Portal](https://portal.fabricbot.ms/bot/?repo=microsoft/PowerShellForGitHub) is the *only way* to modify your FabricBot configuration at the moment, we have a feature on our backlog to publish the JSON schema defining the structure of the FabricBot configuration file. With the JSON schema, you can (1) use a plaintext editor of your choice to modify the FabricBot configuration file and use the schema to validate the file after editing or (2) [configure](https://code.visualstudio.com/Docs/languages/json#_json-schemas-and-settings) VS Code to use the schema when editing FabricBot configuration file to take advantage of convenience features such as automatic code completion and field description on mouseover.

Co-authored-by: msftbot[bot] <48340428+msftbot[bot]@users.noreply.github.com>
Co-authored-by: Howard Wolosky <[email protected]>

Author: msftbot[bot]