dont need that

Gemfile

@@ -14,9 +14,9 @@ gem "minima", "~> 2.5"
 # uncomment the line below. To upgrade, run `bundle update github-pages`.
 # gem "github-pages", group: :jekyll_plugins
 # If you have any plugins, put them here!
-group :jekyll_plugins do
+#group :jekyll_plugins do
-  gem "jekyll-feed", "~> 0.12"
+#  gem "jekyll-feed", "~> 0.12"
-end
+#end
 
 # Windows and JRuby does not include zoneinfo files, so bundle the tzinfo-data gem
 # and associated library.

_config.yml

@@ -28,8 +28,8 @@ github_username:  cesiumcs
 
 # Build settings
 theme: minima
-plugins:
+#plugins:
-  - jekyll-feed
+#  - jekyll-feed
 
 # Exclude from processing.
 # The following items will not be processed, by default.

_posts/2021-04-14-welcome-to-jekyll.markdown

@@ -1,29 +0,0 @@
----
-layout: post
-title:  "Welcome to Jekyll!"
-date:   2021-04-14 14:08:03 -0400
-categories: jekyll update
----
-You’ll find this post in your `_posts` directory. Go ahead and edit it and re-build the site to see your changes. You can rebuild the site in many different ways, but the most common way is to run `jekyll serve`, which launches a web server and auto-regenerates your site when a file is updated.
-
-Jekyll requires blog post files to be named according to the following format:
-
-`YEAR-MONTH-DAY-title.MARKUP`
-
-Where `YEAR` is a four-digit number, `MONTH` and `DAY` are both two-digit numbers, and `MARKUP` is the file extension representing the format used in the file. After that, include the necessary front matter. Take a look at the source for this post to get an idea about how it works.
-
-Jekyll also offers powerful support for code snippets:
-
-{% highlight ruby %}
-def print_hi(name)
-  puts "Hi, #{name}"
-end
-print_hi('Tom')
-#=> prints 'Hi, Tom' to STDOUT.
-{% endhighlight %}
-
-Check out the [Jekyll docs][jekyll-docs] for more info on how to get the most out of Jekyll. File all bugs/feature requests at [Jekyll’s GitHub repo][jekyll-gh]. If you have questions, you can ask them on [Jekyll Talk][jekyll-talk].
-
-[jekyll-docs]: https://jekyllrb.com/docs/home
-[jekyll-gh]:   https://github.com/jekyll/jekyll
-[jekyll-talk]: https://talk.jekyllrb.com/