update: textTheme to use englishLike2018

[ryuash]

Description

closes #61

Checklist

• [x] Targeted PR against correct branch.
• [x] Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• [ ] Wrote unit tests.
• [x] Run flutter format.
• [x] Updated the documentation.
• [x] Added an entry to the CHANGELOG.md file.
• [x] Re-reviewed Files changed in the Github PR explorer.

[codecov[bot]]

Codecov Report

Merging #62 into master will decrease coverage by 0.00%. The diff coverage is 0.00%.

@@            Coverage Diff             @@
##           master      #62      +/-   ##
==========================================
- Coverage   17.77%   17.76%   -0.01%     
==========================================
  Files         254      254              
  Lines        6171     6174       +3     
==========================================
  Hits         1097     1097              
- Misses       5074     5077       +3     

Impacted Files	Coverage Δ
lib/ui/theme/theme.dart	0.00% <0.00%> (ø)

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