Warnings should refer to calling code location.

[cvm-a]

The warnings in the sigfig library are reporting the location of the warning call within the sigfig library, like

/usr/lib/python3.11/site-packages/sigfig/sigfig.py:586: UserWarning: warning: 3 significant figures requested from number with only 1 significant figures

This makes it hard to find out what was the call to sigfig.roud that actually triggered this error. Instead, if we use the stacklevel argument to warn, like

warn("warning: %d significant figures requested from number with only %d significant figures" % (given['sigfigs'], len(num.map)), stacklevel=2)

the error message is like

/my/calling/code.py:270: UserWarning: warning: 3 significant figures requested from number with only 1 significant figures

Can we add the stacklevel argument to all the warning calls?

[MikeBusuttil]

absolutely, good call. Post a PR and it's going in!