Add blog to docs (#484)

* Adding social card infrastructure
* Upgrades doc project to .NET 6
* Adds Playwright
* Changes the console to a web project for Playwright
* Adds social card template
* Added blog content
* Parallelized social image processing
* Updating CI to use .NET 6 for docs build

docs/input/live/index.cshtml

@@ -1,5 +1,6 @@
 Title: Live
-Order: 4
+Order: 50
+Description: Live displays continue to redraw their contents until an action is complete.
 ---
 
 Live displays continue to redraw their contents until an action is complete.

docs/input/live/live-display.md

@@ -1,5 +1,9 @@
 Title: Live Display
 Order: 0
+Description: "*Spectre.Console* can update arbitrary widgets in-place."
+Highlights:
+    - Update tables or graphs with new updates.
+    - Create a custom progress bar that extends the existing control.
 ---
 
 Spectre.Console can update arbitrary widgets in-place.

docs/input/live/progress.md

@@ -1,6 +1,11 @@
 Title: Progress
 Order: 5
 RedirectFrom: progress
+Description: "*Spectre.Console* can display information about long running tasks in the console using progress bars."
+Highlights:
+    - Custom styling of progress bars.
+    - Multiple predefined columns such as Throughput, Estimated Time Remaining, and more.
+    - Fallback for non-interactive consoles such as CI runners.
 ---
 
 Spectre.Console can display information about long running tasks in the console. 

docs/input/live/status.md

@@ -1,6 +1,10 @@
 Title: Status
 Order: 10
 RedirectFrom: status
+Description: "*Spectre.Console* can display information about long running tasks in the console with the Status control."
+Highlights: 
+    - Custom spinner control for running tasks.
+    - Fallback for non-interactive consoles such as CI runners.
 ---
 
 Spectre.Console can display information about long running tasks in the console.