ci: fix workflows triggering on documentation-only changes (#111)

- Fix performance.yml: now ignores *.md, README*, and docs/**
- Fix build.yml: now ignores documentation files and images
- Fix docker.yml: prevent Docker builds on README changes
- Replace 'paths:' with 'paths-ignore:' to properly exclude docs
- Reduces unnecessary CI runs for documentation-only PRs

This resolves the issue where README changes triggered expensive
CI pipelines including Performance Testing and Docker builds.

.github/workflows/performance.yml

@@ -17,11 +17,19 @@ name: Performance Testing
 on:
   push:
     branches: [main]
-    paths:
-      - "rustfs/**"
-      - "crates/**"
-      - "Cargo.toml"
-      - "Cargo.lock"
+    paths-ignore:
+      - "**.md"
+      - "**.txt"
+      - "docs/**"
+      - "deploy/**"
+      - "scripts/dev_*.sh"
+      - "LICENSE*"
+      - "README*"
+      - "**/*.png"
+      - "**/*.jpg"
+      - "**/*.svg"
+      - ".gitignore"
+      - ".dockerignore"
   workflow_dispatch:
     inputs:
       profile_duration: