Add note on NavigateToString limit and common error

[aluhrs13]

Rendered article section for review:

• Working with local content in WebView2 apps > Considerations for loading local content by navigating to an HTML string - added paragraph below heading
  • https://review.learn.microsoft.com/microsoft-edge/webview2/concepts/working-with-local-content?branch=pr-en-us-3236#considerations-for-loading-local-content-by-navigating-to-an-html-string
  • Before/Live

There's a few conversations on Twitter about the size limit of NavigateToString not being obvious, and the error being hard to understand.

This PR replaces a redundant "Additional web resources" section with one calling out the size limit, and including the error string in hopes of improving discoverability.

Outline of headings

# Working with local content in WebView2 apps

<!-- ============================== -->
## Selecting an approach

<!-- ============================== -->
## Loading local content by navigating to a file URL

#### Considerations for loading local content by navigating to a file URL
###### Cross-origin resources
###### Origin-based DOM APIs
###### DOM APIs requiring secure context
###### Dynamic content
###### Additional web resources
###### Additional web resources resolved in WebView2 process

#### APIs for loading local content by navigating to a file URL
#### Example of a file URL
#### Example of navigating to a file URL

<!-- ============================== -->
## Loading local content by navigating to an HTML string

#### Considerations for loading local content by navigating to an HTML string - HERE
###### Origin-based DOM APIs
###### DOM APIs requiring secure context
###### Dynamic content
###### Additional web resources
###### Additional web resources resolved in WebView2 process

#### APIs for loading local content by navigating to an HTML string
#### Example string representation of a webpage
#### Example of navigating to an HTML string

<!-- ============================== -->
## Loading local content by using virtual host name mapping

#### Considerations for loading local content by using virtual host name mapping
###### Origin-based DOM APIs
###### DOM APIs requiring secure context
###### Dynamic content
###### Additional web resources
###### Additional web resources resolved in WebView2 process

#### APIs for loading local content by using virtual host name mapping
#### Example of virtual host name mapping

<!-- ============================== -->
## Loading local content by handling the WebResourceRequested event
#### Custom scheme registration

#### Considerations for loading local content by handling the WebResourceRequested event
###### Origin-based DOM APIs
###### DOM APIs requiring secure context
###### Dynamic content
###### Additional web resources
###### Additional web resources resolved in WebView2 process

#### APIs for loading local content by handling the WebResourceRequested event
#### Example of handling the WebResourceRequested event

<!-- ============================== -->
## See also

AB#52734029

[mikehoffms]

Approved PR after pushed commit for writer/editor review.

[learn-build-service-prod]

Learn Build status updates of commit dbf1880:

✅ Validation status: passed

File	Status	Preview URL	Details
microsoft-edge/docfx.json	✅Succeeded
microsoft-edge/webview2/concepts/working-with-local-content.md	✅Succeeded	View

For more details, please refer to the build report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel

[learn-build-service-prod]

Learn Build status updates of commit 9226f5e:

✅ Validation status: passed

File	Status	Preview URL	Details
microsoft-edge/docfx.json	✅Succeeded
microsoft-edge/webview2/concepts/working-with-local-content.md	✅Succeeded	View

For more details, please refer to the build report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel

[learn-build-service-prod]

Learn Build status updates of commit 5410b1b:

✅ Validation status: passed

File	Status	Preview URL	Details
microsoft-edge/webview2/concepts/working-with-local-content.md	✅Succeeded	View

For more details, please refer to the build report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel