docs: add clnrest to rust plugins and RUST_PROFILE to installation steps

Changelog-None

Author: daywalker90

doc/getting-started/getting-started/installation.md

@@ -134,8 +134,8 @@ pip3 install --upgrade pip
 pip3 install mako
 pip3 install grpcio-tools
 ./configure
-make
-sudo make install
+RUST_PROFILE=release make
+sudo RUST_PROFILE=release make install
 ```
 
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