Add segment coverage ledger and mid-project plan for Crusader decompilation

- Created `crusader_segment_coverage_ledger.csv` to track segment coverage status, types, and known functions.
- Introduced `plan-mid.md` as a mid-project tracker outlining progress, objectives, and implementation priorities for the decompilation effort.
- Added scripts in `pyghidra_plans` to assist with instruction window dumping and reference inspection for the object at `0x4588`.
- Implemented functionality to scan for instruction uses of specific targets related to the decompilation project.

CRUSADER.CFG

@@ -0,0 +1,12 @@
+irq=5
+dma=1
+port=0x220
+soundcard=3
+sound=on
+music=on
+fullinstall=true
+bigvideo=true
+subtitles=true
+
cdletter=D
+flicpath=\flics
+newvideo=true