[docs] Use proper installation command for the fork

'latte-cli' refers to the original latte, not our fork.
So, update the 'install' example command in the README.md file
to have the proper command for any repository, not only original.

README.md

@@ -88,7 +88,7 @@ dpkg -i latte-<version>.deb
 ## From source
 
 1. [Install Rust toolchain](https://rustup.rs/)
-2. Run `cargo install latte-cli`
+2. Run `cargo install --path .`
 
 ## Usage