doc: update README.md

[skip ci]

README.md

@@ -1 +1,52 @@
-## myrc
+# myrc
+
+Symlinking CLI tool for dotfiles (or any other configuration files organized in a directory).
+
+## Install
+
+| Operating system | Link |
+|---|---|
+| Ubuntu 22.04 (Jammy Jellyfish) | [:arrow_upper_right:](https://github.com/kucaahbe/myrc.d/releases/latest) |
+| Ubuntu 20.04 (Focal Fossa) |  [:arrow_upper_right:](https://github.com/kucaahbe/myrc.d/releases/latest) |
+| macOS | [:arrow_upper_right:](https://github.com/kucaahbe/myrc.d/releases/latest) |
+
+### Build
+
+Install [D compiler](https://dlang.org/download.html), `cd` into directory and run `dub`:
+
+```console
+dub build --build=release
+```
+
+#### Build issues
+
+[documented here](build_issues.md)
+
+## Usage
+
+In the directory from where the app is started, the `install.sdl` manifest file is required: there should be specified
+folder installation details:
+
+```
+# the "install" section is mandatory
+install {
+  ln "bashrc", "~/.bashrc"
+  ln "bash_profile", "~/.bash_profile"
+}
+```
+
+Without arguments - shows current state:
+```console
+me@host:~/doftiles$ myrc
+/home/me/dotfiles:
++ /home/me/dotfiles/bashrc -> /home/me/.bashrc
+- /home/me/dotfiles/bash_profile # no such file or directory (need -> /home/me/.bash_profile)
+```
+
+The `install` sub-command issues the install process:
+```console
+me@host:~/doftiles$ myrc
+/home/me/dotfiles install:
+  /home/me/dotfiles/bashrc -> /home/me/.bashrc
+  /home/me/dotfiles/bash_profile -> /home/me/.bash_profile
+```