1 files changed, 15 insertions, 0 deletions
diff --git a/README.md b/README.md
index 0465754..f7cecc5 100644
--- a/README.md
+++ b/README.md
@@ -92,6 +92,11 @@ Here are the options that can be stored in this file:
         "issues": null,
         "contribute": null,
 
+	// Custom links at top of sidebar
+	"custom": {
+	    "Custom link name": "https://customlink.com"
+	},	    	
+
         // Sharing links
         "sharing": {
             "google": null,
@@ -253,3 +258,13 @@ Plugins can used to extend your book's functionality. Read [GitbookIO/plugin](ht
 * [Markdown within HTML](https://github.com/mrpotes/gitbook-plugin-nestedmd): Process markdown within HTML blocks - allows custom layout options for individual pages
 * [Bootstrap JavaScript plugins](https://github.com/mrpotes/gitbook-plugin-bootstrapjs): Use the [Bootstrap JavaScript plugins](http://getbootstrap.com/javascript) in your online GitBook
 * [Piwik Open Analytics](https://github.com/emmanuel-keller/gitbook-plugin-piwik): Piwik Open Analytics tracking for your book
+* [Heading Anchors](https://github.com/rlmv/gitbook-plugin-anchors): Add linkable Github-style anchors to headings
+
+#### Debugging
+
+You can use the environment variable `DEBUG=true` to get better error messages (with stack trace). For example:
+
+```
+$ export DEBUG=true
+$ gitbook build ./
+```