docs(www): better GATSBY_SCREENSHOT_PLACEHOLDER explanation (#10797)

gatsbyjs · Jan 3, 2019 · 62db8e6 · 62db8e6
1 parent e2a6aa1
commit 62db8e6
Showing 1 changed file with 10 additions and 2 deletions.
diff --git a/www/README.md b/www/README.md
@@ -23,6 +23,14 @@ GITHUB_API_TOKEN=YOUR_TOKEN_HERE
 
 The `.env.development` file is ignored by git. Your token should never be committed.
 
-## Screenshots placeholder
+## Running slow build? (Screenshots placeholder)
 
-If you are not working on starter or site showcase, it might be beneficial to use a placeholder image instead of actual screenshots. It will skip downloading screenshots and generating responsive images for all screenshots and replace them with a placeholder image. Check [`gatsby-transformer-screenshot` docs](http://www.gatsbyjs.org/packages/gatsby-transformer-screenshot#placeholder-image) to learn how to use it.
+If you are not working on starter or site showcase, it might be beneficial to use a placeholder image instead of actual screenshots. It will skip downloading screenshots and generating responsive images for all screenshots and replace them with a placeholder image.
+
+Add the following env variable to your `.env.development` file to enable placeholder behaviour:
+
+```
+GATSBY_SCREENSHOT_PLACEHOLDER=true
+```
+
+For more information checkout [`gatsby-transformer-screenshot` docs](http://www.gatsbyjs.org/packages/gatsby-transformer-screenshot#placeholder-image).