docs: add instalation, use and commands section to README.md

README.md

@@ -2,3 +2,38 @@
 
 The [BASH](https://www.gnu.org/software/bash/manual/bash.html#What-is-Bash_003f) project allows for more interactivity with certain console tools, like [Git](https://git-scm.com/) and [NVM](https://github.com/nvm-sh/nvm).
 The project also provides a toolset for easy extension.
+
+## Installation
+
+Put the package content in some of the `PATH` location.
+
+The file `git_switch_branch.sh` has to be put inside the directory. But all other files (those without extensions) can be skipped. If you are not interested with particular command just do not install it.
+
+## Use
+
+After installation, you can use additional commands (unless omitted during [the installation process](#installation)).
+
+## Commands
+
+| Command | Source command | The result command |
+|:----------------------|:---------------|:-------------------------|
+| `git_switch_branch` |`git branch` |`git checkout $selection` |
+| `nvm_select` |`nvm list` |`nvm use $selection` |
+
+### How to find the correct place
+
+You can see the directories listed in the PATH:
+
+```sh
+echo $PATH
+```
+
+On Linux it maybe be usually `~/.local/bin`.
+
+On Windows system you can also use the command:
+
+```bat
+echo %PATH%
+```
+
+but it will be better to open "Environment Variables" and then select "User".