help: Update Message formatting section and page on code blocks.

help/code-blocks.md

@@ -1,40 +1,16 @@
-# Code spans and blocks
+# Code blocks
 
-Zulip supports the standard [Markdown syntax][markdown] for inline
-code spans and code blocks:
+{!code-blocks-intro.md!}
 
-~~~
-Inline code span: `let x = 5`
+## Examples
 
-Code block:
-```
-def f(x):
-   return x+1
-```
-
-Syntax highlighting:
-```python
-def fib(n):
-    # TODO: base case
-    return fib(n-1) + fib(n-2)
-```
-~~~
-
-Sending the above message in Zulip will render like this:
-
-![Markdown code](/static/images/help/markdown-code.png)
-
-You can also use `~~~` to start code blocks, or just indent the code 4 or more
-spaces.
-
-A widget in the top right corner of code blocks allows you to easily
-copy the code to your clipboard.
+{!code-blocks-examples.md!}
 
 ## Language tagging
 
 Tagging a code block with a language enables syntax highlighting and
-(if configured) [code playgrounds](#code-playgrounds). Zulip supports syntax highlighting
-for hundreds of languages.
+(if configured) [code playgrounds](#code-playgrounds). Zulip supports syntax
+highlighting for hundreds of languages.
 
 A code block can be tagged by typing the language name after the fence
 (` ``` `) that begins a code block, as shown here.  Typeahead will
@@ -121,19 +97,16 @@ you can just get the prefix from your browser's URL bar.
 For example, a code block tagged with the "language" `send_tweet` could be
 used with a "playground" that sends the content of the code block as a Tweet.
 
-If you have any trouble setting in setting up a code playground, please [contact
+If you have any trouble setting up a code playground, please [contact
 us](/help/contact-support) with details on what you're trying to do, and we'll
 be happy to help you out.
 
 ## Related articles
 
-[Math blocks][math-block], [spoiler blocks][spoiler-block], and [quote
-blocks][quote-block] use similar fenced block syntax.
+* [Message formatting](/help/format-your-message-using-markdown)
+* [LaTeX](/help/latex)
+* [Spoilers](/help/spoilers)
+* [Quote and reply](/help/quote-and-reply)
 
 [pygments-lexers]: https://pygments.org/docs/lexers/
 [get_lexer_by_name]: https://pygments-doc.readthedocs.io/en/latest/lexers/lexers.html#pygments.lexers.get_lexer_by_name
-
-[markdown]: /help/format-your-message-using-markdown
-[math-block]: /help/format-your-message-using-markdown#latex
-[quote-block]: /help/format-your-message-using-markdown#quotes
-[spoiler-block]: /help/format-your-message-using-markdown#spoilers

help/format-your-message-using-markdown.md

@@ -17,7 +17,7 @@ whenever you need a reminder of the formatting syntax below.
 * [Bulleted lists](#bulleted-lists)
 * [Numbered lists](#numbered-lists)
 * [Links](#links)
-* [Code blocks](#code)
+* [Code blocks](#code-blocks)
 * [LaTeX](#latex)
 * [Quotes](#quotes)
 * [Spoilers](#spoilers)
@@ -51,32 +51,11 @@ whenever you need a reminder of the formatting syntax below.
     <kbd>Shift</kbd> + <kbd>L</kbd>) to insert a link.
     [Learn more](/help/insert-a-link).
 
-## Code
+## Code blocks
 
-~~~
-Inline: `let x = 5`
+{!code-blocks-intro.md!}
 
-Code block:
-```
-def f(x):
-   return x+1
-```
-
-Syntax highlighting:
-```python
-def fib(n):
-    # TODO: base case
-    return fib(n-1) + fib(n-2)
-```
-~~~
-
-![Markdown code](/static/images/help/markdown-code.png)
-
-You can also use `~~~` to start code blocks, or just indent the code 4 or more spaces.
-
-See the main [code blocks article](/help/code-blocks) for details on
-[syntax highlighting](/help/code-blocks#language-tagging), [code
-playgrounds](/help/code-blocks#code-playgrounds), and other features.
+{!code-blocks-examples.md!}
 
 ## LaTeX
 ~~~

help/include/code-blocks-examples.md

@@ -0,0 +1,33 @@
+### What you type
+
+~~~
+Inline code span: `let x = 5`
+
+Code block:
+```
+def f(x):
+   return x+1
+```
+
+Syntax highlighting:
+```python
+def fib(n):
+    # TODO: base case
+    return fib(n-1) + fib(n-2)
+```
+~~~
+
+!!! tip ""
+
+    You can also use `~~~` to start code blocks, or just indent the code 4 or more
+    spaces.
+
+
+### What it looks like
+
+![Markdown code](/static/images/help/markdown-code.png)
+
+!!! tip ""
+
+    A widget in the top right corner of code blocks allows you to easily
+    copy code to your clipboard.

help/include/code-blocks-intro.md

@@ -0,0 +1,4 @@
+You can write snippets of code, code blocks, and other text in a fixed-width
+font using standard Markdown formatting. Zulip also has [syntax
+highlighting](/help/code-blocks#language-tagging) and supports configuring
+custom [code playgrounds](/help/code-blocks#code-playgrounds).