Resolve "doc: use gitpod.io with Froggit.fr"

Closes #59 (closed)

.gitpod.yml

+# This configuration file was automatically generated by Gitpod.
+# Please adjust to your needs (see https://www.gitpod.io/docs/config-gitpod-file)
+# and commit this file to your remote git repository to share the goodness with others.
+
+tasks:
+  - name: Dev Server
+    before: |
+      curl -L https://download.jetbrains.com/fonts/JetBrainsMono-2.242.zip --output /tmp/JetBrainsMono.zip
+      cd /tmp/
+      unzip JetBrainsMono.zip
+      sudo mv fonts/* /usr/share/fonts
+      fc-cache -f -v
+    init: npm install && npm run build
+    command: npm run start
+# Ports to expose on workspace startup
+ports:
+  - port: 3000
+    onOpen: open-browser
+vscode:
+  extensions:
+    - gitlab.gitlab-workflow
+    - pinage404.git-extension-pack
+    - redhat.vscode-yaml
+    - bierner.markdown-preview-github-styles
+    - GitLab.gitlab-workflow
+    - pinage404.git-extension-pack
+    - DavidAnson.vscode-markdownlint
+    - silvenon.mdx
+    - esbenp.prettier-vscode
+    - ecmel.vscode-html-css
+    - zhuangtongfa.material-theme
+    - PKief.material-icon-theme
+    - oderwat.indent-rainbow
+    - tomasvergara.vscode-fontawesome-gallery