chore: Add missing code fence languages (#772)

* chore: Add missing code fence languages

* Update content/actions/creating-actions/dockerfile-support-for-github-actions.md

* Add raw & endraw markers around shell content

See review comment by @rachmari

* Add raw & endraw markers around shell content

See review comment by @rachmari

* Remove language from code fences

to avoid the problem of replaceable text indicates like
<this> not showing up in the output page.

Co-authored-by: hubwriter <hubwriter@github.com>

content/github/writing-on-github/basic-writing-and-formatting-syntax.md

@@ -13,7 +13,7 @@ versions:
 
 To create a heading, add one to six `#` symbols before your heading text. The number of `#` you use will determine the size of the heading.
 
-```
+```markdown
 # The largest heading
 ## The second largest heading
 ###### The smallest heading
@@ -37,7 +37,7 @@ You can indicate emphasis with bold, italic, or strikethrough text.
 
 You can quote text with a `>`.
 
-```
+```markdown
 In the words of Abraham Lincoln:
 
 > Pardon my French
@@ -55,7 +55,7 @@ In the words of Abraham Lincoln:
 
 You can call out code or a command within a sentence with single backticks. The text within the backticks will not be formatted.
 
-```
+```markdown
 Use `git status` to list all new or modified files that haven't yet been committed.
 ```
 
@@ -102,7 +102,7 @@ You can create an inline link by wrapping link text in brackets `[ ]`, and then
 
 You can make an unordered list by preceding one or more lines of text with `-` or `*`.
 
-```
+```markdown
 - George Washington
 - John Adams
 - Thomas Jefferson
@@ -112,7 +112,7 @@ You can make an unordered list by preceding one or more lines of text with `-` o
 
 To order your list, precede each line with a number.
 
-```
+```markdown
 1. James Madison
 2. James Monroe
 3. John Quincy Adams
@@ -126,7 +126,7 @@ You can create a nested list by indenting one or more list items below another i
 
 To create a nested list using the web editor on {% data variables.product.product_name %} or a text editor that uses a monospaced font, like [Atom](https://atom.io/), you can align your list visually. Type space characters in front of your nested list item, until the list marker character (`-` or `*`) lies directly below the first character of the text in the item above it.
 
-```
+```markdown
 1. First list item
    - First nested list item
      - Second nested list item
@@ -140,7 +140,7 @@ To create a nested list in the comment editor on {% data variables.product.produ
 
 In this example, you could add a nested list item under the list item `100. First list item` by indenting the nested list item a minimum of five spaces, since there are five characters (`100. `) before `First list item`.
 
-```
+```markdown
 100. First list item
      - First nested list item
 ```
@@ -149,7 +149,7 @@ In this example, you could add a nested list item under the list item `100. Firs
 
 You can create multiple levels of nested lists using the same method. For example, because the first nested list item has seven spaces (`␣␣␣␣␣-␣`) before the nested list content `First nested list item`, you would need to indent the second nested list item by seven spaces.
 
-```
+```markdown
 100. First list item
      - First nested list item
        - Second nested list item