Adding OWNERS to link_to_text folders.

I'm the original creator of the folder and feature. I also landed
the initial architecture CLs.

Change-Id: Ie73382f1e9a611e853c231691400156e283f4ddb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2485398
Commit-Queue: Rohit Rao <rohitrao@chromium.org>
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#818900}

ios/chrome/browser/link_to_text/OWNERS

+sebsg@chromium.org
+
+# TEAM: ios-directory-owners@chromium.org
+# OS: iOS

ios/chrome/browser/ui/link_to_text/OWNERS

+sebsg@chromium.org
+
+# TEAM: ios-directory-owners@chromium.org
+# OS: iOS