create mixin for code-inline

packages/app/src/styles/atoms/_mixins.scss

@@ -0,0 +1,9 @@
+@use '~/styles/variables' as var;
+@use '~/styles/bootstrap/init' as bs;
+
+@mixin code-inline {
+  padding: 2px 4px;
+  font-family: var.$font-family-monospace-not-strictly;
+  border: 1px solid;
+  border-radius: bs.$border-radius;
+}