Update readme template

Author: rszamszur

template/README.md.jinja

@@ -13,14 +13,18 @@ Prerequisites:
 * copier 6.2.0 or later
 
 ```shell
-copier copy "{{repo_url}}.git" /path/to/your/new/project
+copier copy "{{repo_url}}.git" /path/to/your/new/{{generator_name}}
 ```
 
 ## Using Nix
 
+Prerequisites:
+
+* Nix 2.8.x or later installed [How to install Nix](https://nixos.org/download.html)
+
 ```shell
 nix develop
-copier copy "{{repo_url}}.git" /path/to/your/new/project
+copier copy "{{repo_url}}.git" /path/to/your/new/{{generator_name}}
 ```
 
 ## Updating
@@ -35,9 +39,8 @@ nix run .#update
 
 This action will not update/override your template and its configuration, but rather generators common files:
 
-* Environment (`pyproject.toml` and `poetry.lock`)
-* `README.md`
 * Nix expression files
+* `README.md`
 * dotfiles
 * `LICENSE`
 
@@ -51,5 +54,7 @@ List of excluded files/paths:
 Lastly, you can pass extra copier CLI options should you choose:
 
 ```shell
-./update.sh -x README.md
+./update.sh -x README.md --vcs-ref=custom_branch
+# Or
+nix run .#update -- -x README.md --vcs-ref=custom_branch
 ```