Update _index.md

Author: pareenaverma

content/learning-paths/servers-and-cloud-computing/java-perf-flamegraph/_index.md

@@ -42,16 +42,13 @@ further_reading:
         link: https://wiki.openjdk.org/
         type: documentation
     - resource:
-        title: PLACEHOLDER BLOG 
-        link: PLACEHOLDER BLOG LINK
-        type: blog
-    - resource:
-        title: PLACEHOLDER GENERAL WEBSITE 
-        link: PLACEHOLDER GENERAL WEBSITE LINK
+        title: Java FlameGraphs
+        link: https://www.brendangregg.com/flamegraphs.html
         type: website
 
 
 
+
 ### FIXED, DO NOT MODIFY
 # ================================================================================
 weight: 1                       # _index.md always has weight of 1 to order correctly