Add use of declarativeNetRequest to the "Intercept HTTP requests" guide

[rebloor]

Description

This update:
Modifies the introduction to describe the two APIs available for modifying network requests
- provides parallels of the webRequest redirect requests and modify request headers examples using declarativeNetRequest. As dnr doesn't notify the extension about individual network requests, there is no equivalent to the logging example noted in the introduction section.

To do

Edit to the webRequestsection for:

• Text improvements and paralleling with the new content
• Update to images (if needed to reflect current UI)

Related issues and pull requests

Fixes #32235

[github-actions]

Preview URLs (1 page)

• /en-US/docs/Mozilla/Add-ons/WebExtensions/Intercept_HTTP_requests

External URLs (2)

URL: /en-US/docs/Mozilla/Add-ons/WebExtensions/Intercept_HTTP_requests
Title: Intercept HTTP requests

• https://extensionworkshop.com/documentation/develop/temporary-installation-in-firefox/ (4 times) (Note! This may be a new URL 👀)
• https://useragentstring.com/ (4 times) (Note! This may be a new URL 👀)

(comment last updated: 2026-06-04 19:03:24)