Mono repo -> Master (#22553)

Combines the following repositories into one:

https://github.com/mattermost/mattermost-server
https://github.com/mattermost/mattermost-webapp
https://github.com/mattermost/focalboard
https://github.com/mattermost/mattermost-plugin-playbooks

server/tests/test-markdown-basics.md

@@ -0,0 +1,136 @@
+# Basic Markdown Testing
+Tests for text style, code blocks, in-line code and images, lines, block quotes, and headings.
+
+### Text Style
+
+**The following text should render as:**  
+_Italics_
+_Ita_lics_
+*Italics*
+**Bold**
+***Bold-italics***
+**_Bold-italics_**
+~~Strikethrough~~
+
+This sentence contains **bold**, _italic_, ***bold-italic***, and ~~stikethrough~~ text.  
+
+**The following should render as normal text:**  
+Normal Text_  
+_Normal Text  
+_Normal Text*
+
+### Carriage Return  
+
+Line #1 followed by one blank line 
+
+Line #2 followed by one blank line
+
+Line #3 followed by Line #4
+Line #4 
+
+
+### Code Blocks
+
+```
+This text should render in a code block
+```
+
+**The following markdown should not render:**  
+```
+_Italics_  
+*Italics*  
+**Bold**  
+***Bold-italics***  
+**Bold-italics_**  
+~~Strikethrough~~
+:) :-) ;) ;-) :o :O :-o :-O 
+:bamboo: :gift_heart: :dolls: :school_satchel: :mortar_board:
+# Heading 1
+## Heading 2
+### Heading 3
+#### Heading 4
+##### Heading 5
+###### Heading 6
+> Block Quote
+- List
+  - List Sub-item
+[Link](http://i.giphy.com/xNrM4cGJ8u3ao.gif)
+[![GitHub](https://assets-cdn.github.com/favicon.ico)](https://github.com/mattermost/platform)
+| Left-Aligned Text | Center Aligned Text | Right Aligned Text |
+| :------------ |:---------------:| -----:|
+| Left column 1 | this text       |  $100 |
+```
+
+**The following links should not auto-link or generate previews:**  
+```
+GIF: http://i.giphy.com/xNrM4cGJ8u3ao.gif
+Website: https://en.wikipedia.org/wiki/Dolphin
+```
+
+**The following should appear as a carriage return separating two lines of text:**
+```
+Line #1 followed by a blank line
+
+Line #2 following a blank line
+```
+
+### In-line Code
+
+The word `monospace` should render as in-line code.  
+
+The following markdown in-line code should not render:  
+`_Italics_`, `*Italics*`, `**Bold**`, `***Bold-italics***`, `**Bold-italics_**`, `~~Strikethrough~~`, `:)` , `:-)` , `;)` , `:-O` , `:bamboo:` , `:gift_heart:` , `:dolls:` , `# Heading 1`, `## Heading 2`, `### Heading 3`, `#### Heading 4`, `##### Heading 5`, `###### Heading 6`
+
+This GIF link should not preview: `http://i.giphy.com/xNrM4cGJ8u3ao.gif`  
+This link should not auto-link: `https://en.wikipedia.org/wiki/Dolphin`  
+
+This sentence with `
+in-line code
+` should appear on one line.
+
+### In-line Images
+
+(These image tests were moved into Se: MessagingMan.html)  
+
+
+### Lines
+
+Three lines should render with text between them:  
+
+Text above line
+
+***
+
+Text between lines
+
+---  
+
+Text between lines
+___  
+
+Text below line
+
+### Block Quotes
+
+>This text should render in a block quote.
+
+**The following markdown should render within the block quote:**  
+> #### Heading 4  
+> _Italics_, *Italics*, **Bold**, ***Bold-italics***, **_Bold-italics_**, ~~Strikethrough~~  
+> :) :-) ;) :-O :bamboo: :gift_heart: :dolls:  
+
+**The following text should render in two block quotes separated by one line of text:**
+> Block quote 1
+
+Text between block quotes
+
+> Block quote 2
+
+### Headings
+
+# Heading 1 font size  
+## Heading 2 font size   
+### Heading 3 font size  
+#### Heading 4 font size  
+##### Heading 5 font size  
+###### Heading 6 font size