docs: fix typos in theming docs (react-bootstrap#3463)

* fix typos in theming docs

* fix small nit

Author: bpas247

www/src/pages/getting-started/theming.js

@@ -24,11 +24,11 @@ export default withLayout(function ThemingSection() {
         New variants and sizes
       </LinkedHeading>
       <p>
-        Custom variants and sizes to should follow the leapatternd of the
-        default bootstrap variants, and define css classes matching:{' '}
-        <code>compontent-*</code>. React bootstrap builds the component
-        classNames in a consistent way that you can rely on. For instance this
-        custom Button.
+        Custom variants and sizes should follow the pattern of the default
+        bootstrap variants, and define css classes matching:{' '}
+        <code>component-*</code>. React bootstrap builds the component
+        <code>classNames</code> in a consistent way that you can rely on. For
+        instance this custom Button.
       </p>
       <ReactPlayground codeText={Variants} />
 
@@ -38,7 +38,7 @@ export default withLayout(function ThemingSection() {
       <p>
         In some cases you may need to change the base class "prefix" of one or
         more Components. You can control how a Component prefixes it's classes
-        locallyy by changing the <code>bsPrefix</code> prop. Or globally via the{' '}
+        locally by changing the <code>bsPrefix</code> prop. Or globally via the{' '}
         <code>ThemeProvider</code> Component.
       </p>
       <Callout theme="warning">