Adds automated job to check for broken links in documentation and fixes some links

.github/ISSUE_TEMPLATE/question.md

@@ -10,4 +10,4 @@ Basic questions, related to robot learning, that are not bugs or feature request
 
 Advanced/nontrivial questions, especially in areas where documentation is lacking, are very much welcome.
 
-For questions that are related to running and understanding Isaac Sim, please post them at the official [Isaac Sim forums](https://docs.omniverse.nvidia.com/app_isaacsim/app_isaacsim/isaac_sim_forums.html).
+For questions that are related to running and understanding Isaac Sim, please post them at the official [Isaac Sim forums](https://forums.developer.nvidia.com/c/omniverse/simulation/69).

.github/workflows/check-links.yml

@@ -0,0 +1,120 @@
+# Copyright (c) 2022-2025, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+name: Check Documentation Links
+
+on:
+  # Run on pull requests that modify documentation
+  pull_request:
+    paths:
+      - 'docs/**'
+      - '**.md'
+      - '.github/workflows/check-links.yml'
+  # Run on pushes to main branches
+  push:
+    branches:
+      - main
+      - devel
+      - 'release/**'
+    paths:
+      - 'docs/**'
+      - '**.md'
+      - '.github/workflows/check-links.yml'
+  # Allow manual trigger
+  workflow_dispatch:
+  # Run weekly to catch external links that break over time
+  schedule:
+    - cron: '0 0 * * 0'  # Every Sunday at midnight UTC
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  check-links:
+    name: Check for Broken Links
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+
+    - name: Restore lychee cache
+      uses: actions/cache@v4
+      with:
+        path: .lycheecache
+        key: cache-lychee-${{ github.sha }}
+        restore-keys: cache-lychee-
+
+    - name: Run Link Checker
+      uses: lycheeverse/lychee-action@v2
+      with:
+        # Check all markdown files and documentation
+        args: >-
+          --verbose
+          --no-progress
+          --cache
+          --max-cache-age 1d
+          --exclude-path './docs/_build'
+          --exclude-path './apps/warp-*'
+          --exclude-path './logs'
+          --exclude-path './outputs'
+          --exclude-loopback
+          --exclude '^file://'
+          --exclude '^mailto:'
+          --exclude 'localhost'
+          --exclude '127\.0\.0\.1'
+          --exclude 'example\.com'
+          --exclude 'your-organization'
+          --exclude 'YOUR_'
+          --exclude 'yourdomain'
+          --exclude 'user@'
+          --exclude 'helm\.ngc\.nvidia\.com'
+          --exclude 'slurm\.schedmd\.com'
+          --max-retries 3
+          --retry-wait-time 5
+          --timeout 30
+          --accept 200,201,202,203,204,206,301,302,303,307,308,429
+          --scheme https
+          --scheme http
+          '*.md'
+          '**/*.md'
+          'docs/**/*.rst'
+          'docs/**/*.html'
+        # Output results to a file
+        output: ./lychee-output.md
+        # Fail action on broken links
+        fail: true
+        # Optional: Use GitHub token for authenticated requests (higher rate limit)
+        token: ${{ secrets.GITHUB_TOKEN }}
+
+    - name: Print results to logs
+      if: always()
+      run: |
+        echo "========================================"
+        echo "Link Checker Results:"
+        echo "========================================"
+        if [ -f ./lychee-output.md ]; then
+          cat ./lychee-output.md
+          echo ""
+          echo "========================================"
+
+          # Also add to GitHub step summary for easy viewing
+          echo "## Link Checker Results" >> $GITHUB_STEP_SUMMARY
+          echo "" >> $GITHUB_STEP_SUMMARY
+          cat ./lychee-output.md >> $GITHUB_STEP_SUMMARY
+        else
+          echo "No output file generated"
+          echo "========================================"
+        fi
+
+    - name: Fail job if broken links found
+      if: failure()
+      run: |
+        echo "❌ Broken links were found in the documentation!"
+        echo "Please review the link checker report above and fix all broken links."
+        exit 1

README.md

@@ -87,7 +87,7 @@ innovation in robotics and simulation.
 Please see the [troubleshooting](https://isaac-sim.github.io/IsaacLab/main/source/refs/troubleshooting.html) section for
 common fixes or [submit an issue](https://github.com/isaac-sim/IsaacLab/issues).
 
-For issues related to Isaac Sim, we recommend checking its [documentation](https://docs.omniverse.nvidia.com/app_isaacsim/app_isaacsim/overview.html)
+For issues related to Isaac Sim, we recommend checking its [documentation](https://docs.isaacsim.omniverse.nvidia.com/latest/index.html)
 or opening a question on its [forums](https://forums.developer.nvidia.com/c/agx-autonomous-machines/isaac/67).
 
 ## Support

docs/source/deployment/cluster.rst

@@ -204,7 +204,7 @@ ANYmal rough terrain locomotion training can be executed with the following comm
 The above will, in addition, also render videos of the training progress and store them under ``isaaclab/logs`` directory.
 
 .. _Singularity: https://docs.sylabs.io/guides/2.6/user-guide/index.html
-.. _ETH Zurich Euler: https://scicomp.ethz.ch/wiki/Euler
+.. _ETH Zurich Euler: https://www.gdc-docs.ethz.ch/EulerManual/site/overview/
 .. _PBS Official Site: https://openpbs.org/
 .. _apptainer: https://apptainer.org/
 .. _documentation: https://www.apptainer.org/docs/admin/main/installation.html#install-ubuntu-packages