add coverage badge to readme (#8)

README.md

@@ -9,6 +9,12 @@
 <p align="center">
    <a href="https://vazco.eu">
         <img src="https://img.shields.io/badge/vazco-package-blue.svg?logo=data%3Aimage%2Fpng%3Bbase64%2CiVBORw0KGgoAAAANSUhEUgAAAA4AAAAOCAYAAAAfSC3RAAAABmJLR0QA%2FwD%2FAP%2BgvaeTAAAACXBIWXMAAAsTAAALEwEAmpwYAAAAB3RJTUUH4QMfFAIRHb8WQgAAAY1JREFUKM%2BNkLFrGgEUxr87FMnpnXdIqxi1Q3VxachgSbcOgRBCTMbgH9CCW%2BjSUminSpEmBEIpHW7rkCmQSSjEKVOGEAK5bOFyk4c5TMRTyZ1fl5aK9ai%2F8b334%2Ft4QBBmLQmz9jpoLSKYPQCfYdaezi6atTKAMoAYgK1pJ8LkQPr5JspHsbO%2BFilAEADQArCA3Ftn%2FC40KebPO4Ln37peNNxrFxPSXTaW9cPiewDbgYkkXwBYB3B5dHES3W8cpM254ctOJhr3wsKqs7Zj%2FdOZZITkMf9yT%2FKq3e18eHf47fmTT5XE1H%2BQ3GAwDyQ%2FkkxMSvLvhP%2FxZVLc42zYJBf%2FSPMkW57nsd%2Fv03VdDgYDjkajIPkryVDIdd1Xtm0%2Fdhznptvtmr7vu5IkRRRFySiKko%2FH45BlebzgJoBdodls%2FjAM49SyrIau69etVmsIIFStVnPFYvFZoVBY1jRtJZlMpjRNm5MkCaIofhfq9XrMMIyeruuc9u1KpRIulUqqqqpLqqqW0%2Bl0OZVKyb8ANqUwunhV3dcAAAAASUVORK5CYII%3D" />
+   </a>
+   <a href="https://codecov.io/gh/vazco/uniforms-cli">
+        <img src="https://img.shields.io/codecov/c/github/vazco/uniforms-cli.svg" alt="Coverage" />
+    </a>
+   <a href="https://npmjs.org/package/uniforms">
+        <img src="https://img.shields.io/npm/l/uniforms.svg" alt="License" />
     </a>
      <a href="https://github.com/vazco/uniforms-cli/actions?query=branch:main">
         <img src="https://img.shields.io/github/actions/workflow/status/vazco/uniforms-cli/CI.yml" alt="Status" />