Add relevant usage migration guide (#23891)

* Add relevant usage migration guide

* Address feedback, including adding the new response examples

* Fix JSON and make minor wording changes

* Small format fixes

* Apply suggestions from code review

Co-authored-by: Sandra (neko) <[email protected]>

* replace 'may' with 'might'

* remove v2 and v1 from endpoint names to reduce confusion

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Co-authored-by: Sandra (neko) <[email protected]>

Author: urseberry

content/en/account_management/guide/_index.md

@@ -9,6 +9,7 @@ cascade:
 ---
 
 {{< whatsnext desc="Usage metering API migration guides:" >}}
+    {{< nextlink href="account_management/guide/relevant-usage-migration" >}}Migrate Indexed Logs and RUM in the Hourly Usage and Summary Usage APIs{{< /nextlink >}}
     {{< nextlink href="account_management/guide/hourly-usage-migration" >}}Migrating from the v1 Hourly Usage APIs to v2{{< /nextlink >}}
     {{< nextlink href="account_management/guide/usage-attribution-migration" >}}Migrating from v1 to v2 of the Usage Attribution API{{< /nextlink >}}
     {{< nextlink href="account_management/guide/csv-headers-billing-migration" >}}Updates to Plan & Usage CSV Headers as of September 18, 2023{{< /nextlink >}}