README has invalid HTML for badges

[jamiehaywood]

Describe the bug
The readme files contains html with no closing tags which cannot be parsed by Docusaurus.

Expected behavior
READMEs contain valid HTML

Information

• Day.js Version [e.g. v1.0.0]
• OS: [e.g. iOS]
• Browser [e.g. chrome 62]
• Time zone: [e.g. GMT-07:00 DST (Pacific Daylight Time)]

[iamkun]

fixed thanks