Update docs: Simplify links to opcodes
<p>While ASM makes everything very simple it does not mean you should dive head-first into editing compiled java programs without understanding some basic programming concepts and the Java class file design. Here are some references for these topics:</p>
<ul>
<li>Java class file specification: <a href="https://docs.oracle.com/javase/specs/jvms/se10/html/jvms-4.html">Specification: Chapter 4. The class File Format</a></li>
- <li>Java opcodes: <a href="opcodes.html">Simplified ASM set</a> | <a href="https://cs.au.dk/~mis/dOvs/jvmspec/ref-Java.html">Standard set</a></li>
+ <li>Java opcodes:
+ <ul>
+ <li><a href="opcodes.html">Simplified ASM set</a></li>
+ <li><a href="https://cs.au.dk/~mis/dOvs/jvmspec/ref-Java.html">Standard set</a></li>
+ </ul>
+ </li>
<li><a href="https://blog.takipi.com/jvm-architecture-101-get-to-know-your-virtual-machine/">JVM Architecture 101: Get to Know Your Virtual Machine</a></li>
</ul>
