docs: add comprehensive documentation and fix github actions

- add docs/ with installation, usage, modules, scans, and api docs
- add docs link to main readme
- fix release.yml to bundle modules directory with releases
- add module system tests to runtest.yml
- standardize go version to 1.23 across workflows

.github/workflows/runtest.yml

@@ -27,3 +27,16 @@ jobs:
             echo "Sif exited with an error"
             exit 1
           fi
+
+      - name: Test module system
+        run: |
+          echo "Listing modules..."
+          ./sif -lm
+          echo "Running all modules..."
+          ./sif -u https://example.com -am
+          if [ $? -eq 0 ]; then
+            echo "Module system working"
+          else
+            echo "Module system failed"
+            exit 1
+          fi