Add gitignore and tt_lesson snippet. Advances #1.

.gitignore

+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+
+# pyenv
+.python-version
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+
+# Editors
+*~
+DEADJOE
+\#*#
+
+# Database
+db.sqlite3

biscuit/apps/chronos/templates/chronos/tt_lesson.html

+<div class="card" style="width: 18rem; {{% if Lesson.color-fg %}} foreground-color: {{ Lesson.color-fg }}; {% endif%} {{% if Lesson.color-bg %}} background-color: {{% Lesosn.color-bg %}};">
+  <div class="card-body">
+    <h5 class="card-title">{{ Lesson.subject.abbrev }}</h5>
+    <h6 class="">Rooms {# Will be implemented soon#}</h6>
+    <ul>
+     <li>{{ Lesson.teachers }}</li>
+     <li>{{ Lesson.groups }}</li>
+    </ul>
+    <a href="{{% '#' %}}" class="card-link">Room informations</a>
+  </div>
+</div>