give weight to merged PR types

[Hebilicious]

this might be controversial, but we could have introduce weight to calculate the points for the PRs:

• docs: 1x
• chore: 1x
• style: 1x
• build: 2x
• ci: 2x
• refactor: 2x
• test: 2x
• perf: 3x
• fix: 3x
• feat: 3x

While everything is important, I think it makes the system a little more fun and rewarding.