libsurvive: Link to README.md instead of having outdated instructions

Closes monado#237

libsurvive.md

@@ -5,15 +5,14 @@ layout: main
 
 # The libsurvive driver in Monado
 
-Before enabling the libsurvive driver in Monado, libsurvive has to be installed as a library before compiling monado. For example with cmake and ninja
-```
-git clone https://github.com/cntools/libsurvive.git
-cd libsurvive
-cmake -DCMAKE_INSTALL_PREFIX=/usr -G Ninja -DCMAKE_BUILD_TYPE=Release -Bbuild
-ninja -C build install
-```
+Before enabling the libsurvive driver in Monado, libsurvive has to be installed as a library before compiling monado. You can follow the build instructions from the [README.md](https://github.com/cntools/libsurvive), make sure to install it as well.
 
-To check whether Monado was built with libsurvive support, run `monado-cli probe` and check whether it appears in the list of `Built in drivers`.
+To check whether Monado will be built with libsurvive look at the output from CMake and look for:
+
+```txt
+-- #    DRIVER_SURVIVE:      ON
+```
+You can also do a runtime check if Monado was built with libsurvive support, run `monado-cli probe` and check whether it appears in the list of `Built in drivers`.
 
 When starting any libsurvive or OpenXR application, libsurvive will use cached calibration in `$XDG_CONFIG_HOME/libsurvive/config.json`, or `~/.config/libsurvive/config.json` or run a fresh calibration if this config does not exist yet.