Add install-lsp subcommand

.cargo/config

@@ -3,6 +3,8 @@
 gen-syntax   = "run --package tools --bin tools -- gen-syntax"
 # Extracts the tests from
 gen-tests    = "run --package tools --bin tools -- gen-tests"
+# Installs ra_lsp_server
+install-lsp = "install --path crates/ra_lsp_server --force"
 # Installs the visual studio code extension
 install-code = "run --package tools --bin tools -- install-code"
 # Formats the full repository or installs the git hook to do it automatically.

README.md

@@ -29,6 +29,8 @@ $ cargo run --package ra_cli parse < crates/ra_syntax/src/lib.rs
 $ cargo run --package ra_cli symbols < crates/ra_syntax/src/lib.rs
 
 # install the language server
+$ cargo install-lsp
+or
 $ cargo install --path crates/ra_lsp_server
 ```