Embedded-STS 2.0.0

 * [`fixed`]   Improved compatibility with C++ compilers
 * [`changed`] Return types are now `int16_t` instead of `int8_t` (in line with
               other embedded drivers).
 * [`changed`] Functions are now dedicated per sensor (e.g. `sts3x_probe()`
               instead of `sts_probe()`)
 * [`changed`] Move the i2c init call out of `probe()` and into the example
 * [`changed`] Rename `git_version.[ch]` to `sts_git_version.[ch]`
 * [`added`]   Add `sts3x_read_serial()` to read out the serial number
 * [`changed`] Split out `default_config.inc` from Makefile to configure paths
               and CFLAGS
 * [`changed`] Only one example with either `hw_i2c` or `sw_i2c` is built,
               depending on `CONFIG_I2C_TYPE`. Defaults to `hw_i2c`.
 * [`fixed`]   Measurement duration could take at most 15.5ms (datasheet) but we
               only waited 15ms
 * [`added`]   Add `STS3X_MEASUREMENT_DURATION_USEC` to header
 * [`changed`] Fix compilation warnings when compiling the linux user space
               sample implementation with `CONFIG_I2C_TYPE` set to `sw_i2c`
 * [`removed`] Remove the `AUTHORS` file from the driver and the
               `embedded-common` submodule, as it adds more noise than benefit.
               The contributors can be found in the git log.
 * [`fixed`]   Copy correct `CHANGELOG.md` and `LICENSE` files to target
               locations when running the `release` target of the driver's root
               Makefile.