README fix for external ingress

[ganadurai]

Description

Fixes recommended https://github.com/apigee/devrel/issues/612

Issues Fixed

• Fixes #

Housekeeping

(please check all that apply [x], do not edit the text)

• [x] I have run all the tests locally and they all pass.
• [x] I have followed the relevant style guide for my changes.

Full Repo Validation Required

(please check all that apply [x], do not edit the text)

• [ ] PR requires full pipeline run (Run for changes only by default).

CC: @apigee-devrel-reviewers

[danistrebel]

/gcbrun

[apigee-devrel-bot]

Pipeline Report

Pipeline	Result	Elapsed Wall Time
TOTAL PIPELINE (no change)	pass	0

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Commit version: dd33c6e

[danistrebel]

thanks a lot @ganadurai