chore: add some important comments

_config.yml

@@ -1,3 +1,23 @@
+# Welcome to Jekyll!
+#
+# About Theme
+#
+# Yet another theme for elegant writers with modern flat style and beautiful
+# night/dark mode.
+#
+# Website: https://github.com/jeffreytse/jekyll-theme-yat
+#
+# You can do anything you want, including projects for your clients, as long
+# as you mention an attribution back (credit links in footer or project).
+# See the LICENCE file.
+#
+# This config file is meant for settings that affect your whole blog, values
+# which you are expected to set up once and rarely edit after that.
+#
+# For technical reasons, this file is *NOT* reloaded automatically when you
+# use 'bundle exec jekyll serve'. If you change this file, please restart
+# the server process.
+#
 # Site settings
 # These are used to personalize your new site. If you look in the HTML files,
 # you will see them accessed via {{ site.title }}, {{ site.email }}, and so on.