[FEATURE] Add the ability for multiple News feeds (and update the default feed)

[LorneCash]

The default news feed is https://vsstartpage.blob.core.windows.net/news/vs but the last news published on that feed was on Tue, 09 Nov 2021. Firstly, and strait away I would suggest that you update that link to something that's at least still updated like https://devblogs.microsoft.com/visualstudio/feed/.

Doing further research, I stumbled across a new News extension by Mads Kristensen called Developer News. I went poking around the source code and found the feed url he used. That's where I got the one I listed above from but really I should have said one of the feed urls because there's many. Here's the link where I found them. I've also listed them below for easy reference. Maybe there's some code there you can use too but really now I'm just wishing that I could add several of them. I'm thinking you could just allow them to be specified in a comma separated list but I think it would be great to also list a source name next to the date so it would appear like this:

Title
Summary line 1
Summary line 2
Date Feed Name

I'd fully support making a new UI to do that but I know changing the UI sucks so I thought an easy way to do that might be to specify them like this with a pipe bar separating the name and a comma separating items:
feed url|feed name, feed url|feed name, etc.

And you could always come back and update the UI later. If you were considering updating the UI I'd like to see checkboxes to enable and disable them rather than just adding and deleting but I feel like you've probably got more urgent things to do.

Again thanks for all you've done and here's the full list from the link above.

On a side note, even right now, you might want to put this list in your README as suggestions for news feeds people could use.

Visual Studio - https://devblogs.microsoft.com/visualstudio/feed/
.NET - https://devblogs.microsoft.com/dotnet/feed/
Azure Blog - https://azurecomcdn.azureedge.net/en-us/blog/feed/
Azure DevOps - https://devblogs.microsoft.com/devops/feed/
Azure SDKs - https://devblogs.microsoft.com/azure-sdk/feed/
C++ - https://devblogs.microsoft.com/cppblog/feed/
Command Line - https://devblogs.microsoft.com/commandline/feed/
CosmosDB - https://devblogs.microsoft.com/cosmosdb/feed/
DirectX - https://devblogs.microsoft.com/directx/feed/
IoT - https://devblogs.microsoft.com/iotdev/feed/
Microsoft 365 - https://devblogs.microsoft.com/microsoft365dev/feed/
NuGet - https://devblogs.microsoft.com/nuget/feed/
Old New Thing - https://devblogs.microsoft.com/oldnewthing/feed/
PowerShell - https://devblogs.microsoft.com/powershell/feed/
Python - https://devblogs.microsoft.com/python/feed/
Q# - https://devblogs.microsoft.com/qsharp/feed/
SQL Server - https://cloudblogs.microsoft.com/sqlserver/feed/
TypeScript - https://devblogs.microsoft.com/typescript/feed/
VS Office Hours - https://www.youtube.com/feeds/videos.xml?playlist_id=PLReL099Y5nRem6UA4w849hTfd0LzBIsAk
VS Tips & Tricks - https://www.youtube.com/feeds/videos.xml?playlist_id=PLReL099Y5nRc-zbaFbf0aNcIamBQujOxP
Xamarin - https://devblogs.microsoft.com/xamarin/feed/
Visual Studio Code - https://code.visualstudio.com/feed.xml
Windows Developer - https://blogs.windows.com/windowsdeveloper/feed/