docs: Add information about spike-dasm installation

docs/ug/getting_started.md

@@ -55,8 +55,18 @@ export CC="gcc-9.2.0"
 export CXX="g++-9.2.0"
 export LLVM_BINROOT="/usr/pack/riscv-1.0-kgf/pulp-llvm-0.12.0/bin"
 # As a temporary workaround (until correct tool versions are installed system-wide):
-export PATH=/home/colluca/snitch/bin:$PATH
 export PATH=/usr/scratch/dachstein/colluca/opt/verible/bin:$PATH
+
+# Install spike for spike-dasm (submodule of the repository)
+cd sw/deps/riscv-isa-sim
+autoconf
+mkdir build
+cd build
+../configure
+make
+export PATH=$(pwd):$PATH
+# or use temporary:
+# export PATH=/home/colluca/snitch/bin:$PATH
 ```
 
 Add these commands to your shell startup file (e.g. `~/.bashrc` if you use bash as the default shell) to ensure that the environment is set up correctly every time you open a new shell.