Add note on drafts (#4305)

content/en/docs/contributing/_index.md

@@ -76,7 +76,7 @@ class first,second white
 
 _Figure 1. Contributing new content._
 
-The previous figure presents the basic steps for new docs contributions.
+The previous figure illustrates how to contribute new documentation.
 
 To contribute new content pages or improve existing content pages, open a pull
 request (PR):
@@ -86,6 +86,14 @@ request (PR):
 - If your changes are large, read [Work from a local fork](#fork-the-repo) to
   learn how to make changes locally on your computer.
 
+{{% alert title="Tip" %}}
+
+Turn your pull request into a draft to signal that the content still isn't ready
+for review. Maintainers may still comment or do high-level reviews, though they
+won't review the content in full until you remove the draft status.
+
+{{% /alert %}}
+
 ### Changes using GitHub {#changes-using-github}
 
 If you're less experienced with Git workflows, here's an easier method of
@@ -124,12 +132,12 @@ _Figure 2. Steps for opening a PR using GitHub._
 1. On the page where you see the issue, select the **Edit this page** option in
    the right-hand side navigation panel.
 
-1. If you're not a member of the project, GitHub will offer to create a fork of
-   the repository. Select **Fork this repository**.
+1. If you're not a member of the project, GitHub offers to create a fork of the
+   repository. Select **Fork this repository**.
 
 1. Make your changes in the GitHub editor.
 
-1. Below the editor, fill in the **Propose file change** form.
+1. Fill in the **Propose file change** form.
 
 1. Select **Propose file change**.