Merge pull request #644 from snyk/chore/add-learn-to-api-ref-toc

added learn to api reference toc

Author: mikeromard

docs/SUMMARY.md

@@ -957,6 +957,7 @@
   * [Invites](snyk-api/reference/invites.md)
   * [Issues](snyk-api/reference/issues.md)
   * [Jira (v1)](snyk-api/reference/jira-v1.md)
+  * [Learn](snyk-api/reference/learn.md)
   * [Licenses (v1)](snyk-api/reference/licenses-v1.md)
   * [Monitor (v1)](snyk-api/reference/monitor-v1.md)
   * [OpenSourceSettings](snyk-api/reference/opensourcesettings.md)