Fix font-override in blog and docs (#3448)

This prevents it from overriding font for code blocks and helps retain monosapce font for them.

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#### Does this PR need a docs update or release note?

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- [ ] 🕐 Yes, but in a later PR
- [x] ⛔ No

#### Type of change

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- [ ] 🌻 Feature
- [ ] 🐛 Bugfix
- [x] 🗺️ Documentation
- [ ] 🤖 Supportability/Tests
- [ ] 💻 CI/Deployment
- [ ] 🧹 Tech Debt/Cleanup

#### Issue(s)

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#### Test Plan

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- [x] 💪 Manual
- [ ] ⚡ Unit test
- [ ] 💚 E2E

website/src/css/custom.scss

@@ -6,8 +6,8 @@ CUSTOM TO THE NEW HOME PAGE
 @import "icons.scss";
 @import url('https://fonts.googleapis.com/css2?family=Nunito&display=swap');
 
-* {
+:root {
-  font-family: 'Nunito', sans-serif !important;
+  --ifm-font-family-base: 'Nunito', sans-serif;
 }
 
 html {