Docs: Added a Markdown Style Guide (#22425)

* Docs: Adding a Markdown Style Guide

What this PR does / why we need it: This request builds a markdown style guide for writers documenting information about Grafana services for users.
This PR serves the need to make documentation and READMEs more consistent and maintainable.

Which issue(s) this PR fixes: This request fixes the issue grafana#19592

Fixes grafana#19592

Special notes for your reviewer:

@marcusolsson and @oddlittlebird, sorry for the delay. I've set up the style guide, and it is ready for review, or additional sections.

* Docs: Adding a Markdown Style Guide

What this PR does / why we need it: This request builds a markdown style guide for writers documenting information about Grafana services for users.
This PR serves the need to make documentation and READMEs more consistent and maintainable.

Which issue(s) this PR fixes: This request fixes the issue grafana#19592

Fixes grafana#19592

Special notes for your reviewer:

@marcusolsson and @oddlittlebird, sorry for the delay. I've set up the style guide, and it is ready for review, or additional sections.

* Docs: fixing typos and char repetition

Editing some typos in the text, and removing the repetition of A and B characters that appeared in the file.

* Docs: Changing content following review of new Markdown Style Guide

- adjustment to headings to sentence case.
- adding an introduction
- removing punctuation content
- making suggested word and punctuation fixes

Fixes #19592

contribute/style-guides/documentation-markdown-guide.md

@@ -0,0 +1,144 @@
+# Markdown style guide
+
+This guide for Markdown style helps keep contributions consistent across all documentation
+created for Grafana products. Refer to the guide and update its sections as needed when a
+Subject Matter Expert answers a question on Markdown style, or a decision is made about
+how to apply Markdown.
+
+## Headers
+
+In Markdown, the number of "#" symbols creates different heading levels, similar to
+HTML heading levels:
+
+**Example**
+
+* \# is \<h1>.
+* \#\# is \<h2>.
+* \#\#\# is \<h3>.
+
+Start your document with a single ``#`` for the title of the page. Add the sub-headings with two ``##``.
+
+## Bold and emphasis
+
+* Make text **bold** using two asterisks.
+
+**Example:** It is ``**important**`` to use Github Flavored Markdown emoji consistently.
+
+* Make text ``*emphasized*`` using single `` _underscores_`` or a single asterisk.
+
+**Example:** Github Flavored Markdown emoji should _only_ appear in specific cases.
+
+
+## Links and references
+
+Create links to other website by wrapping the display text in square brackets, and
+the web URL in curved brackets.
+
+\[text to display](www.website.com)
+
+**Example:** For more information on including emoji in Github flavored Markdown, refer to the [webfx page on emoji](https://www.webfx.com/tools/emoji-cheat-sheet/) for a list of emoji.
+
+## Block quotes
+
+Include Block quotes inside text using right-facing arrows:
+
+**Example**
+
+> Any important information
+> about emoji can be separated into
+> a blockquote.
+
+## Code blocks
+
+Code blocks written with markdown can show off syntax highlighting specific
+to different languages. Use three back tics to create a code block:
+
+```
+function testNum(a) {
+  if (a > 0) {
+    return "positive";
+  } else {
+    return "NOT positive";
+  }
+}
+```
+
+Write the name of the language after the first set of back tics, no spaces,
+to show specific syntax highlighting. For example; "\```javascript" produces the following:
+
+```javascript
+function testNum(a) {
+  if (a > 0) {
+    return "positive";
+  } else {
+    return "NOT positive";
+  }
+}
+```
+## Tables
+
+Construct a table by typing the table headings, and separating them with
+a "|" character. Then, add a second line of dashes ("-") separated by
+another "|" character. When constructing the table cells, separate each cell data with another
+"|".
+
+**Example**
+
+Heading one | Heading two
+
+\------------|------------
+
+Cell one data| Cell two data
+
+Will publish as:
+
+Heading one | Heading two
+------------|------------
+Cell one data| Cell two data
+
+## Lists
+
+### Numbered lists
+
+To avoid inconsistent list numbering, use repetitive list numbering:
+
+\1. First
+
+\1. Second
+
+\1. Third
+
+The list above will always display as:
+
+1. First
+2. Second
+3. Third
+
+### Unordered lists
+
+Build a list of points - an unordered or unnumbered list - by
+using "\*" characters.
+
+**Example**
+
+* First
+* Another item
+* The last list item
+
+## Images
+
+Include images in a document using the following syntax:
+
+**Example** \!\[Grafana Logo](/link/to/grafanalogo/logo.png)
+
+This follows the format of "!", alt text wrapped in "[]" and the link URL wrapped in "()".
+
+## Comments
+
+You can include comments that will not appear in published markdown using the
+following syntax:
+
+\[comment]: <> (Comment text to display)
+
+The word "comment" wrapped in "[]" followed by a ":", a space, "<>", and then
+the comment itself wrapped in "()".