Add Icon and Color Tokens for Soliton Calendar

[NIbokeefe]

Color Tokens:

New % Variants of NI-Tulip (#E54C8A):
NI-Tulip 10
NI-Tulip 15
NI-Tulip 20
NI-Tulip 30
NI-Tulip 60

BrownDark - #9B7A60
BrownDark 10
BrownDark 15
BrownDark 20
BrownDark 30
BrownDark 60
BrownDark 100

BrownLight - #6F4E37
LightBrownDark 10
LightBrownDark 15
LightBrownDark 20
LightBrownDark 30
LightBrownDark 60
LightBrownDark 100

Icon Token
Name: Job
Tags: Work

[jattasNI]

Some related tokens got added in #2837 but looks like this is another batch. @vivinkrishna-ni do you plan to add these ones too?

[vivinkrishna-ni]

@jattasNI Yes, we will plan to add these colors and an icon to the Nimble.