Add New Themes for UI

[Ma-Yueran]

Galaxy Theme:

Sky Theme (Cannot think of a better name...)

[codecov-io]

Codecov Report

Merging #276 into master will decrease coverage by 0.06%.
The diff coverage is 36.36%.

@@             Coverage Diff              @@
##             master     #276      +/-   ##
============================================
- Coverage     64.17%   64.11%   -0.07%     
- Complexity      550      552       +2     
============================================
  Files           100      100              
  Lines          1823     1831       +8     
  Branches        192      192              
============================================
+ Hits           1170     1174       +4     
- Misses          578      582       +4     
  Partials         75       75              

Impacted Files	Coverage Δ	Complexity Δ
src/main/java/seedu/address/ui/ThemeWindow.java	0.00% <0.00%> (ø)	0.00 <0.00> (ø)
src/main/java/seedu/address/ui/theme/ThemeSet.java	90.00% <100.00%> (+6.66%)	5.00 <0.00> (+2.00)

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[luo-git]

Looks good. The words in galaxy theme is a bit hard to read though.

Another thing, could you update the UG as well?

[Ma-Yueran]

Looks good. The words in galaxy theme is a bit hard to read though.

Another thing, could you update the UG as well?

Sure, I try to add theme switching to UG

[Ma-Yueran]

Looks good. The words in galaxy theme is a bit hard to read though.
Another thing, could you update the UG as well?

Sure, I try to add theme switching to UG

Ooo, just found it's already added, then I will update the images.

[luo-git]

Looks good. The words in galaxy theme is a bit hard to read though.
Another thing, could you update the UG as well?

Sure, I try to add theme switching to UG

Ooo, just found it's already added, then I will update the images.

The changing theme section is not updated to reflect your changes. Could you also update the screenshot if possible?

Changing themes
HelloFile comes in light and dark themes. ...

[Ma-Yueran]

Looks good. The words in galaxy theme is a bit hard to read though.
Another thing, could you update the UG as well?

Sure, I try to add theme switching to UG

Ooo, just found it's already added, then I will update the images.

The changing theme section is not updated to reflect your changes. Could you also update the screenshot if possible?

Changing themes
HelloFile comes in light and dark themes. ...

Sure, I'm doing that now

[Ma-Yueran]

The color of the edge of the window for me is white,

But others are blue,

How do I modify the color to make it consistent?

[Ma-Yueran]

Galaxy Theme is updated to make fonts clearer,

[luo-git]

How do I modify the color to make it consistent?

Doesn't matter for now. We probably need to change those screenshots later because the words are too small...😢

[luo-git]

LGTM!