[Docs] Fix the illustration of plugin workflow (1a1a11a#288)

* Fix the illustration of plugin workflow

* Update TOC

* Update note

Author: haochengxia

doc/README.md

@@ -1,15 +1,19 @@
+# CacheSim Documentation
 
-## Main tools
-* [cachesim](quickstart_cachesim.md)
-* [trace utils](quickstart_traceUtils.md)
-* [trace analysis](quickstart_traceAnalysis.md)
+## Quickstart Guides
+- [CacheSim: Command-line cache simulator](quickstart_cachesim.md)
+- [Trace Utilities](quickstart_traceUtils.md)
+- [Trace Analyzer](quickstart_traceAnalyzer.md)
+- [MRC Profiler](quickstart_mrcProfiler.md)
+- [Plugin System](quickstart_plugin.md)
 
-## Using libCacheSim as a library
-* [library](lib.md)
-* [add a new algorithm](lib_extend.md)
-* [API](lib_api.md)
-
-
-## Benchmarks
-* [benchmarks](quickstart_benchmarks.md)
+## Advanced Usage
+- [Library Usage Guide](advanced_lib.md)
+- [How to Add a New Algorithm](advanced_lib_extend.md)
+- [API Reference (C)](API.md)
+- [Performance Tuning](performance.md)
+- [Memory Usage Profiling](memory_usage_profiling.md)
 
+## Developer Documentation
+- [Debugging Guide](debug.md)
+- [Install & Build](install.md)

doc/quickstart_plugin.md

@@ -17,7 +17,7 @@ graph LR
     D -->|No| F{libCacheSim Cache Full?}
     F -->|Yes| G["cache_eviction_hook()<br/>plugin cache determines the object(s) to evict"]
     F -->|No| H["cache_miss_hook()<br/>Update plugin cache stats"]
-    G --> H
+    G --> F
 
     style E fill:#bfb,stroke:#333,stroke-width:2px
     style G fill:#fbb,stroke:#333,stroke-width:2px
@@ -300,6 +300,23 @@ For Python examples, see the `libCacheSim-python/README.md` file which contains
 * **Performance Issues**: Use `process_trace()` for large workloads instead of individual `get()` calls for better performance.
 * **Memory Usage**: Monitor cache statistics (`cache.occupied_byte`) and ensure proper cache size limits for your system.
 * **Custom Cache Issues**: Validate your custom implementation against built-in algorithms using test functions.
+* **Implementation Issues**: When re-implementing an eviction algorithm in libCacheSim using the plugin system, note that the core hook functions are simplified. This may introduce some challenges. The central function for cache simulation is `get` and its common internal logic is:
+
+  ```mermaid
+  graph LR
+      C["find() (Cache state is updated automatically, since update_cache = true by default)"] --> D{Found in cache?}
+      D -->|Yes| E["cache_hit_hook()"]
+      D -->|No| F{"Cache full?"}
+      F -->|"Yes (no space for new object)"| G["cache_eviction_hook()"]
+      F -->|No| H["cache_miss_hook()"]
+      G --> F
+
+      style E fill:#bfb,stroke:#333,stroke-width:2px
+      style G fill:#fbb,stroke:#333,stroke-width:2px
+      style H fill:#bbf,stroke:#333,stroke-width:2px
+  ```
+
+  Because find is not exposed to plugins, any state-update logic that normally happens inside find must instead be implemented inside the relevant hook functions (cache_hit_hook, cache_eviction_hook, or cache_miss_hook) according to your algorithm’s needs.
 
 ---