Add a new unit angstrom

[singularitti]

While deprecated by the IBWM and the NIST, the unit is still often used in the natural sciences and technology to express sizes of atoms, molecules, microscopic biological structures, and lengths of chemical bonds, the arrangement of atoms in crystals, wavelengths of electromagnetic radiation, and dimensions of integrated circuit parts. --Wiki

[coveralls]

Pull Request Test Coverage Report for Build 45

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 100.0%

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Totals
Change from base Build 44:	0.0%
Covered Lines:	61
Relevant Lines:	61

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💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 45

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 100.0%

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Totals
Change from base Build 44:	0.0%
Covered Lines:	76
Relevant Lines:	76

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💛 - Coveralls

[codecov-io]

Codecov Report

Merging #4 into master will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff          @@
##           master     #4   +/-   ##
=====================================
  Coverage     100%   100%           
=====================================
  Files           1      1           
  Lines          15     16    +1     
=====================================
+ Hits           15     16    +1

Impacted Files	Coverage Δ
src/UnitfulAtomic.jl	100% <ø> (ø)	⬆️

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[sostock]

Thanks for the PR!

Since the ångström is based on an SI unit (1 Å = 10⁻¹⁰ m), I feel like it would fit better in Unitful.jl. For example, the barn (1 b = 10⁻²⁸ m²) is also defined in Unitful.jl and not in UnitfulAtomic.jl.

Would you be fine with creating a PR for Unitful.jl instead? If it is rejected for whatever reason, I will gladly merge this.

[singularitti]

OK, I will have a try.

[sostock]

Since PainterQubits/Unitful.jl#271 is now merged, I am closing this.