docs: update README

README.md

@@ -11,46 +11,68 @@ Lua environment manager built on top of [hererocks](https://github.com/luarocks/
 
 ## Installation
 
- 1. Install `luamb` using `pip` (`hererocks` will be installed automatically):
+ 1. Install luamb using `pip`:
 
  ```sh
  pip install [--user] luamb
  ```
 
- 2. Create a directory for environments:
+  or `pipx`:
 
  ```sh
- mkdir $HOME/.luambenvs
+ pipx install luamb
  ```
 
- 3. Configure your shell (add these lines to `~/.bashrc` or `~/.zshrc`):
+ 2. Set up your shell — add the following to `~/.bashrc` or `~/.zshrc`:
 
  ```sh
- # path to the directory with environments
- export LUAMB_DIR=$HOME/.luambenvs
-
- # optional variables:
- export LUAMB_LUA_DEFAULT='lua 5.3' # default Lua version
- export LUAMB_LUAROCKS_DEFAULT=latest # default LuaRocks version
- LUAMB_DISABLE_COMPLETION=true # disable shell completions
- LUAMB_PYTHON_BIN=/usr/bin/python3 # explicitly set Python executable
-
- # make some magic
  source <(luamb shellsrc)
- # or if luamb executable is not in PATH:
- source <("$LUAMB_PYTHON_BIN" -m luamb shellsrc)
  ```
 
- 4. Try to execute in a new shell:
+ 3. Install hererocks:
 
  ```sh
- luamb --help
+ luamb update
  ```
 
 
+## Configuration
+
+luamb is configured via environment variables.
+
+ * `LUAMB_HOME`
+
+ A directory where luamb stores its data (hererocks, environments, etc.). The default value is `$XDG_DATA_HOME/luamb` (usually `~/.local/share/luamb`) on Linux and `~/Library/Application Support/luamb` on macOS.
+
+ * `LUAMB_ENVS_DIR`
+
+ A directory where luamb stores environments. The default value is `$LUAMB_HOME/envs`.
+
+ * `LUAMB_LUA_DEFAULT`
+
+ A default Lua interpreter/version. The format is `interpreter version_specifier`, e.g., `lua 5.3`, `luajit @v2.1`, `moonjit /path/to`, `raptorjit latest`.
+
+ * `LUAMB_LUAROCKS_DEFAULT`
+
+ A default LuaRocks version, e.g, `latest`, `3.11.0`.
+
+ * `LUAMB_DISABLE_COMPLETION`
+
+ Set to `true` to disable shell completions.
+
+ * `LUAMB_PYTHON_BIN`
+
+ If the luamb executable is not in `PATH`, set `LUAMB_PYTHON_BIN` to the Python executable with the `luamb` package installed and change the shell initialization command:
+
+ ```sh
+ export LUAMB_PYTHON_BIN=/path/to/bin/python
+ source <("$LUAMB_PYTHON_BIN" -m luamb shellsrc)
+ ```
+
+
 ## Examples
 
- * Create an environment 'myproject' with the latest Lua 5.2 (5.2.4), the latest LuaRocks and associate it with /home/user/projects/myproject:
+ * Create an environment 'myproject' with the latest Lua 5.2, the latest LuaRocks and associate it with /home/user/projects/myproject:
 
  ```sh
  luamb mk myproject -l 5.2 -r latest -a /home/user/projects/myproject
@@ -62,7 +84,7 @@ Lua environment manager built on top of [hererocks](https://github.com/luarocks/
  luamb mk jittest -j 2.0.4 -a /home/user/projects/jitproj
  ```
 
- * Set the latest LuaJIT 2.0 (2.0.5) and the latest LuaRocks version by default:
+ * Set the latest LuaJIT 2.0 and the latest LuaRocks as default versions:
 
  ```sh
  export LUAMB_LUA_DEFAULT='luajit 2.0'
@@ -75,7 +97,7 @@ Lua environment manager built on top of [hererocks](https://github.com/luarocks/
  luamb mk newenv
  ```
 
- * Create an environment 'norocks' with the default Lua version (LuaJIT 2.0.5) and without LuaRocks (verbose mode):
+ * Create an environment 'norocks' with the default Lua version and without LuaRocks (verbose mode):
 
  ```sh
  luamb mk norocks --no-luarocks --verbose
@@ -102,14 +124,14 @@ Lua environment manager built on top of [hererocks](https://github.com/luarocks/
 
 ## Commands
 
-Each command has one or more aliases.
-
  * `on` | `enable` | `activate` — activate an environment
  * `off` | `disable` | `deactivate` — deactivate the current environment
  * `mk` | `new` | `create` — create a new environment
  * `rm` | `remove` | `del` | `delete` — remove an environment
  * `info` | `show` — Show the details for a single virtualenv
  * `ls` | `list` — list all of the environments
+ * `update` — install/update the `hererocks` script
+ * `shellsrc` — print the shell initialization code
 
 
 ## Version history