docs: add caching to workflow and link to dev docs in README

- Add julia-actions/cache to speed up documentation builds
- Add dev docs badge and links in README
- Clarify stable vs dev documentation for users

Author: ChenKaihuang

.github/workflows/Documentation.yml

@@ -22,6 +22,7 @@ jobs:
       - uses: julia-actions/setup-julia@v1
         with:
           version: '1.10'
+      - uses: julia-actions/cache@v2
       - name: Install dependencies
         run: julia --project=docs -e 'using Pkg; Pkg.develop(PackageSpec(path=pwd())); Pkg.instantiate()'
       - name: Build and deploy

README.md

@@ -1,11 +1,14 @@
 # HPR-LP: A GPU Solver for Linear Programming
 
 [![Documentation](https://img.shields.io/badge/docs-stable-blue.svg)](https://polyu-ior.github.io/HPR-LP/)
+[![Documentation](https://img.shields.io/badge/docs-dev-blue.svg)](https://polyu-ior.github.io/HPR-LP/dev/)
 [![CI](https://github.com/PolyU-IOR/HPR-LP/actions/workflows/CI.yml/badge.svg)](https://github.com/PolyU-IOR/HPR-LP/actions/workflows/CI.yml)
 
 > **A Julia implementation of the Halpern Peaceman-Rachford (HPR) method for solving linear programming (LP) problems on the GPU.**
 
-**📖 [Read the Documentation](https://polyu-ior.github.io/HPR-LP/)**
+**📖 Documentation:**
+- **[Stable](https://polyu-ior.github.io/HPR-LP/)** - Latest released version (v0.1.3)
+- **[Dev](https://polyu-ior.github.io/HPR-LP/dev/)** - Latest from main branch (recommended for development)
 
 ---