chore(docker,docs): improve npm reliability and update feature documentation

- Configure npm fetch retries and timeouts in Dockerfile to handle network issues during dependency installation
- Set fetch-retries to 5, fetch-retry-mintimeout to 60s, fetch-retry-maxtimeout to 300s, and fetch-timeout to 600s
- Update README.md feature descriptions for improved clarity and accuracy
- Add bookmark preservation notes to Merge PDFs and Alternate & Mix Pages tools
- Add new features: Rotate by Custom Degrees, PDF Booklet, PDF Form Filler, Deskew PDF, and Font to Outline
- Enhance PDF Editor description with specific capabilities (annotate, highlight, redact, comment, shapes, images, search)
- Reorganize feature table entries for better logical grouping
- Remove duplicate "Fill Forms" entry in favor of new PDF Form Filler tool

Dockerfile

@@ -8,7 +8,11 @@ WORKDIR /app
 COPY package*.json ./
 COPY vendor ./vendor
 ENV HUSKY=0
-RUN npm ci
+RUN npm config set fetch-retries 5 && \
+    npm config set fetch-retry-mintimeout 60000 && \
+    npm config set fetch-retry-maxtimeout 300000 && \
+    npm config set fetch-timeout 600000 && \
+    npm ci
 COPY . .
 
 # Build without type checking (vite build only)