message: Add script to generate ssl_roots.h from Mozilla's CA bundle
  Cr-Commit-Position: refs/heads/main@{#36131}
diff: @@ -4,20 +4,18 @@ This directory contains a script to generate the content of
  [rtc_base/ssl_roots.h][ssl-roots-header], to update the SSL roots shipped
  by WebRTC follow this instructions:
  -1. Download roots.pem from [pki.goog][pki-goog].
  +1. Download roots.pem from [pki.goog][pki-goog] or [curl.se][mozilla-cacert]
  2. Launch the script:
  ```
  -$ vpython3 tools_webrtc/sslroots/generate_sslroots.py roots.pem
  +$ vpython3 tools_webrtc/sslroots/generate_sslroots.py <the pem file>
  ```
  -3. Step 2 should have generated an ssl_roots.h file right next to roots.pem.
  +3. Step 2 should have generated an ssl_roots.h file right next to the pem file.
  -4. Open rtc_base/ssl_roots.h, manually remove the old certificates and paste
  - the ones from the ssl_roots.h file.
  -
  -5. Delete the generated ssl_roots.h and roots.pem before creating the CL.
  +4. Overwrite rtc_base/ssl_roots.h with the newly generated one.
  [ssl-roots-header]: https://cs.chromium.org/chromium/src/third_party/webrtc/rtc_base/ssl_roots.h
  [pki-goog]: https://www.google.com/url?q=https://pki.google.com/roots.pem
  +[mozila-cacert]: https://curl.se/ca/cacert.pem
  