Fix casing for consistency (#5881)

There's 5 instances in this document in which the casing of a file name
begins with lower case, which makes it inconsisnent both with the page
and the entire tutorial.

src/content/learn/importing-and-exporting-components.md

@@ -138,10 +138,10 @@ How you export your component dictates how you must import it. You will get an e
 
 | Syntax           | Export statement                           | Import statement                          |
 | -----------      | -----------                                | -----------                               |
-| Default  | `export default function Button() {}` | `import Button from './button.js';`     |
-| Named    | `export function Button() {}`         | `import { Button } from './button.js';` |
+| Default  | `export default function Button() {}` | `import Button from './Button.js';`     |
+| Named    | `export function Button() {}`         | `import { Button } from './Button.js';` |
 
-When you write a _default_ import, you can put any name you want after `import`. For example, you could write `import Banana from './button.js'` instead and it would still provide you with the same default export. In contrast, with named imports, the name has to match on both sides. That's why they are called _named_ imports!
+When you write a _default_ import, you can put any name you want after `import`. For example, you could write `import Banana from './Button.js'` instead and it would still provide you with the same default export. In contrast, with named imports, the name has to match on both sides. That's why they are called _named_ imports!
 
 **People often use default exports if the file exports only one component, and use named exports if it exports multiple components and values.** Regardless of which coding style you prefer, always give meaningful names to your component functions and the files that contain them. Components without names, like `export default () => {}`, are discouraged because they make debugging harder.
 
@@ -257,8 +257,8 @@ You may use either a default or a named export for `Profile`, but make sure that
 
 | Syntax           | Export statement                           | Import statement                          |
 | -----------      | -----------                                | -----------                               |
-| Default  | `export default function Button() {}` | `import Button from './button.js';`     |
-| Named    | `export function Button() {}`         | `import { Button } from './button.js';` |
+| Default  | `export default function Button() {}` | `import Button from './Button.js';`     |
+| Named    | `export function Button() {}`         | `import { Button } from './Button.js';` |
 
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