update README with info about the removal of free-pro-team from URLs

Author: sarahs

content/README.md

@@ -24,6 +24,7 @@ See the [contributing docs](/CONTRIBUTING.md) for general information about work
   - [Escaping single quotes](#escaping-single-quotes)
 - [Autogenerated mini TOCs](#autogenerated-mini-tocs)
 - [Versioning](#versioning)
+  - [Free-pro-team vs. GitHub.com versioning](#free-pro-team-vs.-github.com-versioning)
 - [Filenames](#filenames)
 - [Whitespace control](#whitespace-control)
 - [Links and image paths](#links-and-image-paths)
@@ -213,6 +214,12 @@ A content file can have **two** types of versioning:
 * Liquid statements in content (**optional**)
     * Conditionally render content depending on the current version being viewed. See [contributing/liquid-helpers](../contributing/liquid-helpers.md) for more info. Note Liquid conditionals can also appear in `data` and `include` files.
 
+### Free-pro-team vs. GitHub.com versioning
+
+As of early 2021, the `free-pro-team@latest` version is **only** supported in content files (in both frontmatter and Liquid versioning) and throughout the docs site backend. It is **not** user facing. A helper function called `lib/remove-fpt-from-path.js` removes the version from URLs. Users now select `GitHub.com` in the Article Versions dropdown instead of `Free, Pro, Team`.
+
+The convenience function allows us to continue supporting a consistent versioning structure under-the-hood while not displaying plan information to users that may be potentially confusing.
+
 ## Filenames
 
 When adding a new article, make sure the filename is a [kebab-cased](https://en.wikipedia.org/wiki/Letter_case#Special_case_styles) version of the title you use in the article's [`title`](#title) frontmatter. This can get tricky when a title has punctuation (such as "GitHub's Billing Plans"). A test will flag any discrepancies between title and filename. To override this requirement for a given article, you can add [`allowTitleToDifferFromFilename`](#allowtitletodifferfromfilename) frontmatter.
@@ -224,7 +231,7 @@ When using Liquid conditionals in lists or tables, you can use [whitespace contr
 Just add a hyphen on either the left, right, or both sides to indicate that there should be no newline on that side. For example, this statement removes a newline on the left side:
 
 ```
-{%- if page.version == 'dotcom' %}
+{%- if currentVersion == 'free-pro-team@latest' %}
 ```
 
 These characters are especially important in [index pages](#index-pages) comprised of list items.
@@ -238,9 +245,9 @@ For example, if you include the following link in a content file:
 ```
 /github/writing-on-github/creating-a-saved-reply
 ```
-When viewed on GitHub.com docs, the link gets rendered with the language code and version:
+When viewed on GitHub.com docs, the link gets rendered with the language code:
 ```
-/en/free-pro-team@latest/github/writing-on-github/creating-a-saved-reply
+/en/github/writing-on-github/creating-a-saved-reply
 ```
 and when viewed on GitHub Enterprise Server docs, the version is included as well:
 ```