Fix missing docs example for "Mnemonics which contain a period"

[kinverarity1]

[dcslagel]

@kinverarity1,

This doesn't look like it is updated/corrected in the Lasio online documents at:
https://lasio.readthedocs.io/en/latest/header-section.html?highlight=period#mnemonics-which-contain-a-period

However it is updated (the example displays) if I build the docs locally so the docs probably just need to be updated.

DC

[dcslagel]

@kinverarity1,

One additional thing, which may just be a problem with my local setup so just checking. When I run rstcheck, or rest2pseudoxml on the rst files they display a Warning/Error for the .. code-block:: none entries:
Cannot analyze code. No Pygments lexer found for "none".

Do you get these messages also? If you don't see them, then I have some misconfiguration in my document-building environment.

DC