Create book and deploy it to the website (#6)

* Create book structure.
* Add workflow for linting the markdown using markdownlint.
* Add workflow for building the book with mdBook and deploying to the website.
* Restyle mdBook and support GitHub-style alerts.
* Add images zooming.
* Add index, firmware structure and gyroscope articles.

docs/alerts.py

@@ -0,0 +1,31 @@
+# https://rust-lang.github.io/mdBook/format/configuration/preprocessors.html
+# https://rust-lang.github.io/mdBook/for_developers/preprocessors.html
+
+import json
+import sys
+import re
+
+
+def transform_markdown_to_html(markdown_text):
+    def replace_blockquote(match):
+        tag = match.group(1).lower()
+        content = match.group(2).strip().replace('\n> ', ' ')
+        return f'<div class="alert alert-{tag}">{content}</div>\n'
+
+    pattern = re.compile(r'> \[!(NOTE|TIP|IMPORTANT|WARNING|CAUTION)\]\n>(.*?)\n?(?=(\n[^>]|\Z))', re.DOTALL)
+    transformed_text = pattern.sub(replace_blockquote, markdown_text)
+    return transformed_text
+
+
+if __name__ == '__main__':
+    if len(sys.argv) > 1:
+        if sys.argv[1] == 'supports':
+            sys.exit(0)
+
+    context, book = json.load(sys.stdin)
+
+    for section in book['sections']:
+        if 'Chapter' in section:
+            section['Chapter']['content'] = transform_markdown_to_html(section['Chapter']['content'])
+
+    print(json.dumps(book))