Multiple enhancements and bugfixes

!Breaking change! - The updated version will not be able to read your old database file

Major improvements:
- Added editable pastas
- Added private pastas
- Added line numbers
- Added support for wide mode (1080p instead of 720p)
- Added syntax highlighting support
- Added read-only mode
- Added built-in help page
- Added option to remove logo, change title and footer text

Minor improvements:
- Improved looks in pure html mode
- Removed link to GitHub repo from navbar
- Broke up 7km long main.rs file into smaller modules
- Moved water.css into a template instead of serving it as an external resource
- Made Save button a bit bigger
- Updated README.MD

Bugfixes:
- Fixed a bug where an incorrect animal ID in a request would cause a crash
- Fixed a bug where an empty or corrupt JSON database would cause a crash

templates/edit.html

@@ -0,0 +1,20 @@
+{% include "header.html" %}
+<form method="POST" enctype="multipart/form-data">
+    <h4>
+        Editing pasta '{{ pasta.id_as_animals() }}'
+    </h4>
+    <label>Content</label>
+    <br>
+    <textarea style="width: 100%; min-height: 100px" name="content" id="content" autofocus>{{ pasta.content }}</textarea>
+    <br>
+
+    {% if args.readonly %}
+    <input style="width: 140px; background-color: limegreen" disabled type="submit" value="Read Only"/>
+    {%- else %}
+    <input style="width: 140px; background-color: limegreen" type="submit" value="Save"/>
+    {%- endif %}
+    </td>
+
+    <br>
+</form>
+{% include "footer.html" %}