defines font monospace in theme

Author: vdusart

src/@chakra-ui/gatsby-plugin/foundations/fonts.ts

@@ -0,0 +1,6 @@
+const fonts = {
+  monospace:
+    "SFMono-Regular, Consolas, 'Roboto Mono', 'Droid Sans Mono', 'Liberation Mono', Menlo, Courier, monospace",
+}
+
+export default fonts

src/@chakra-ui/gatsby-plugin/foundations/index.ts

@@ -1,10 +1,12 @@
 import colors from "./colors"
+import fonts from "./fonts"
 import shadows from "./shadows"
 
 // Check the following link to see all the possible options:
 // https://github.com/chakra-ui/chakra-ui/blob/main/packages/theme/src/foundations/index.ts
 const foundations = {
   colors,
+  fonts,
   shadows,
 }