v0.1.8 - Add a command delay and increase serial timeout.

Add a command delay and increase serial timeout.

Fix an arbitrary wave upload data corruption issue
which was sometimes happening when uploading waves
and then running other commands immediately
afterwards. Adding a 50 millisecond delay at the
beginning of every command which communicates
with the device seems to have fixed it.

Increase serial communication timeout from 3
seconds to 6 seconds, which improves communication
stability when issuing scripted commands in rapid
succession.

Move contents of tools/ folder into examples/ folder
and delete empty tools/ folder.

Add examples/clear-user-waves.sh - A bash script
which clears all the user-defined arbitrary waveform
save slot data, by writing a flat line wave centered
at 0 volts into each slot.

Add examples/load-random-waves.sh - A bash script
which overwrites all the user-defined arbitrary
waveform save slots with new randomly generated
waveforms, using the bash shell's built-in $RANDOM
variable for the source of randomness.

Add examples/load-crypto-random-waves.sh - A bash
script which overwrites all the user-defined
arbitrary waveform save slots with new randomly
generated waveforms, using the operating system's
built-in /dev/urandom more secure source of
randomness.

Update GitLab CI/CD config so that it should run
a lot faster now.

Update the crate homepage in Cargo.toml so it
points to the GitLab signal-gen-cjds66-lib/
subfolder page.

Improve wording, formatting, and instructions
in README.md.

Add more links in README.md.

Add a section at the bottom of README.md mentioning
the three new bash scripts in the examples/ folder.