Document basic commissioning procedure

[martukas]

What is required
Start documentation on how a newly build ventilator unit should be commissioned. Once the software has been deployed, what steps need to be taken for initial configuration. My current guess is:

• set and confirm serial number
• manually set any constants for installed components, e.g. valve or venturi coefficients determined by physical configuration
• perform any automatic calibration procedures
• register unit with online database and give it an authentication token - for test data submission and error reporting
• ???

How do you know it has to be done
We already have units with different PSOLs, for example. We will not be building hacked or ifdeffed code to configure them as this would be a maintenance nightmare.

Starting points
Serial number is already configurable via debug interface. Once at least #1273 is done, it should be possible to write a procedure for PSOL configuration. With other related calibration tickets - same for even more components. As progress is made on https://github.com/RespiraWorks/test-data-browser , an authentication token should also become available.

[martukas]

PSOL constants that have been recently hard-coded:

// UFlow IBV19M values
static constexpr float PSolClosed{0.35f};
static constexpr float PSolOpen{0.75f};

// SMC PVQ31-40 values
static constexpr float PSolClosed{0.35f};
static constexpr float PSolOpen{0.95f};

But ideally should be experimentally tuned using calibration scripts.

[martukas]

Related ticket and comments in #376