Added note about arsh shell

blog/posts.org

@@ -1,4 +1,3 @@
 #+title: Blog posts
 * 2025
-- [[./framework12guix.org][GNU Guix on Framework 12]]
 - [[./whythiswebsiteissimple.org][Why this website is so simple?]]

index.org

@@ -15,6 +15,7 @@ Since November 2025 I'm also an associated member of [[https://fsf.org][Free Sof
 - [[./projects/project-gestalt.org][Project Gestalt (Mod for Stellaris)]]
 - [[./projects/health-for-watch.org][Health for Watch]]
 - To be continued...
+- [[./projects/arsh.org][arsh - a simple shell]]
 * [[./blog/posts.org][My Blog]]
 * My Contributions
 I contributed to several Free and Open Source projects:

projects/arsh.org

@@ -0,0 +1,18 @@
+#+title: arsh - ARchaic SHell
+
+Since I started using GNU/Linux, I always wondered, how do shells work and what exactly are they responsible for. 
+
+In order to learn it (and also to use some C) I decided to implement a simple shell in C in a /single file/, where I would try to implement some of the features, that other shells like bash, zsh, fish, etc have. And also I wanted to use no external dependencies, except for the standard C library.
+
+* Features
+Some of the implemented features are:
+- You can pipe stdout of one command to stdin of another (ex. ~cat main.c | wc --lines~)
+- You can redirrect output/input with ~>~, ~>>~, ~<~, ~2>~, ~&>~
+- Variables expansion with ~$PATH~ and ~${HOME}~ syntax
+- Shows custom prompt, if ~PS1~ env variable is set
+- Run subcomands with ~$(hostname)~ or ~`pwd`~ (works with pipes)
+- Custom ~readline~ function with support for cursor moving (<-, ->) and inline editing
+- Run the shell in interactive and non interactive mode
+
+* Source code
+[[https://git.kylekrein.com/kylekrein/arsh][Forgejo]]