Updated docs to reflect that getEntry returns undefined

src/content/docs/en/guides/content-collections.mdx

@@ -409,12 +409,29 @@ Once queried, you can render Markdown and MDX entries to HTML using the [`render
 import { getEntry, render } from 'astro:content';
 
 const entry = await getEntry('blog', 'post-1');
+if(!entry){
+  // Handle Error
+}
 const { Content, headings } = await render(entry);
 ---
 <p>Published on: {entry.data.published.toDateString()}</p>
 <Content />
 ```
 
+`getEntry()` returns either an entry object or `undefined`.
+
+1. Conditional Check (Recommended)
+```ts
+if (!entry) {
+  //Handle Error
+}
+```
+2. Non-Null Assertion Operator
+```ts
+// Use the ! operator to assert the value is non-null
+const { Content, headings, remarkPluginFrontmatter } = await render(entry!);
+```
+
 #### Passing content as props
 
 A component can also pass an entire collection entry as a prop.

src/content/docs/en/reference/modules/astro-content.mdx

@@ -209,10 +209,31 @@ A function to compile a given entry for rendering. This returns the following pr
 ---
 import { getEntry, render } from 'astro:content';
 const entry = await getEntry('blog', 'entry-1');
+
+
+// Handle undefined return
+if (!entry) {
+  //Handle Error
+}
 const { Content, headings, remarkPluginFrontmatter } = await render(entry);
 ---
 ```
 
+`getEntry()` returns either an entry object or `undefined`.
+
+1. Conditional Check (Recommended)
+```ts
+if (!entry) {
+  //Handle Error
+}
+```
+2. Non-Null Assertion Operator
+```ts
+// Use the ! operator to assert the value is non-null
+const { Content, headings, remarkPluginFrontmatter } = await render(entry!);
+```
+
+
 [See the `Content Collection` guide](/en/guides/content-collections/#rendering-body-content) for example usage.
 
 ## `astro:content` types