Remove old theme

src/utils/theme.ts

-import { Heading, Link } from 'rebass';
-
-const theme = {
-  breakpoints: [545, 1024, 1440, 1920],
-  colors: {
-    red: '#f8485e',
-    darkgray: '#3d3d3d',
-  },
-  space: [0, 4, 8, 16, 32, 64, 128, 256, 512].map(value => `${value / 16}rem`),
-  fonts: {
-    sans: 'Montserrat, system-ui, sans-serif',
-    mono: '"Roboto Mono", monospace',
-  },
-  fontWeights: {
-    bold: 600,
-  },
-  Heading: {
-    fontWeight: 500,
-    textTransform: 'lowercase',
-  },
-  Link: {
-    padding: '0.125em 0',
-    textDecoration: 'none',
-    'p &:hover': {
-      background: '#f8485e',
-      color: 'white',
-    },
-  },
-};
-
-Heading.defaultProps = {
-  ...Heading.defaultProps,
-  as: 'h1',
-  fontSize: '2rem',
-  fontFamily: 'mono',
-};
-
-Link.defaultProps = {
-  ...Link.defaultProps,
-  color: 'red',
-};
-
-export default theme;