Fix typos in the "External Application Properties" section

See gh-28830

Author: fml2

spring-boot-project/spring-boot-docs/src/docs/asciidoc/features/external-config.adoc

@@ -354,7 +354,7 @@ It's not uncommon to use environment variables for such purposes, but this can h
 As an alternative to environment variables, many cloud platforms now allow you to map configuration into mounted data volumes.
 For example, Kubernetes can volume mount both https://kubernetes.io/docs/tasks/configure-pod-container/configure-pod-configmap/#populate-a-volume-with-data-stored-in-a-configmap[`ConfigMaps`] and https://kubernetes.io/docs/concepts/configuration/secret/#using-secrets-as-files-from-a-pod[`Secrets`].
 
-There are two common volume mount patterns that can be use:
+There are two common volume mount patterns that can be used:
 
 . A single file contains a complete set of properties (usually written as YAML).
 . Multiple files are written to a directory tree, with the filename becoming the '`key`' and the contents becoming the '`value`'.
@@ -504,7 +504,7 @@ WARNING: Multi-document property files cannot be loaded by using the `@PropertyS
 
 [[features.external-config.files.activation-properties]]
 ==== Activation Properties
-It's sometimes useful to only activate a given get of properties when certain conditions are met.
+It's sometimes useful to only activate a given set of properties when certain conditions are met.
 For example, you might have properties that are only relevant when a specific profile is active.
 
 You can conditionally activate a properties document using `spring.config.activate.*`.