fix syntax errors

Author: ColtonRandall

src/app/__tests__/page.test.tsx

@@ -20,7 +20,7 @@ describe('HomePage Component', () => {
     render(<HomePage />)
     const textarea = screen.getByRole('textbox')
     expect(textarea).toBeInTheDocument()
-    expect(textarea).toHaveAttribute('placeholder', 'Paste code here... ')
+    expect(textarea).toHaveAttribute('placeholder', 'Paste code here... ');
   })
 
   it('renders explain button', () => {

src/app/api/explain/__tests__/route.test.ts

@@ -92,7 +92,7 @@ describe('POST /api/explain', () => {
           {
             role: 'system',
             content:
-              'You are a helpful programming assistent. Explain the provided code clearly, concisely, and simply.',
+              'You are a helpful programming assistant. Explain the provided code clearly, concisely, and simply.',
           },
           {
             role: 'user',

src/app/api/explain/route.ts

@@ -21,7 +21,7 @@ export async function POST(req: Request) {
           {
             role: "system",
             content:
-              "You are a helpful programming assistent. Explain the provided code clearly, concisely, and simply.",
+              "You are a helpful programming assistant. Explain the provided code clearly, concisely, and simply.",
           },
           {
             role: "user",