Support more units

[Zh40Le1ZOOB]

Such as dm, mm³ , cm³ , dm³ , m³ etc.

[sivelswhy]

also converting speeds
like : mp/h to km/h etc

[deefrawley]

More units added in v2.0.0.
I plan to add more but will keep this issue open so anyone can request conversaions they would like to use in the plugin

[Lucas256-cmd]

I could use conversions for pressure like Pa, kPa, bar, atm, ...
Thanks in advance
Really good pugin btw, does everything it has to. I just had an issue with the rounding but the solution was found in issue 24

[alexwhittemore]

Any chance for supporting arbitrary definitions?

My requests are for small distance units:

• um (microns/micrometers)
• nm (nanometers)
• thou (thousandths of an inch)
• mil (thousandths of an inch also)
• tenths (ten thousandths of an inch)
• Maybe also angstroms (but I don't need them)