Rename image files to lowercase to comply with naming conventions

Author: yinyu01

content/learning-paths/servers-and-cloud-computing/java-perf-flamegraph/1_setup.md

@@ -42,9 +42,9 @@ vim apache-tomcat-11.0.9/webapps/examples/META-INF/context.xml
 
 4. If you can access the page at "http://${tomcat_ip}:8080/examples" via a browser, congratulations-you can proceed to the next benchmarking step.
 
-![example image alt-text#center](./_images/LP-tomcat-homepage.png "Tomcat-HomePage")
+![example image alt-text#center](./_images/lp-tomcat-homepage.png "Tomcat-HomePage")
 
-![example image alt-text#center](./_images/LP-tomcat-examples.png "Tomcat-Examples")
+![example image alt-text#center](./_images/lp-tomcat-examples.png "Tomcat-Examples")
 
 ## Setup Benchmark Client - [wrk2](https://github.com/giltene/wrk2)
 - wrk2 is a high-performance HTTP benchmarking tool specialized in generating constant throughput loads and measuring latency percentiles for web services.

content/learning-paths/servers-and-cloud-computing/java-perf-flamegraph/2_async-profiler.md

@@ -27,4 +27,4 @@ cd async-profiler-4.0-linux-arm64/bin
 
 3. Launch profile.html in a browser to analyse the profiling result
 
-![example image alt-text#center](_images/LP-flamegraph-async.png "Java Flame Graph via async-profiler")
+![example image alt-text#center](_images/lp-flamegraph-async.png "Java Flame Graph via async-profiler")

content/learning-paths/servers-and-cloud-computing/java-perf-flamegraph/3_agent.md

@@ -35,4 +35,4 @@ sudo perf inject -j -i perf.data | perf script | stackcollapse-perf.pl | flamegr
 
 4. Launch profile.svg in a browser to analyse the profiling result
 
-![example image alt-text#center](_images/LP-flamegraph-agent.png "Java Flame Graph via Java agent and perf")
+![example image alt-text#center](_images/lp-flamegraph-agent.png "Java Flame Graph via Java agent and perf")