doc: fix the make configurator fails issue
The current code need python3.8-venv to build some modules, so we
should add these requirement to "Getting Started Guide".
This patch modify the getting-started.rst to generate new guide.
@@ -132,6 +132,7 @@ To set up the ACRN build environment on the development computer:
libusb-1.0-0-dev \
python3 \
python3-pip \
+ python3.8-venv \
libblkid-dev \
e2fslibs-dev \
pkg-config \
