Add env-based configuration of TTL of Tomcat's static resource cache

Closes gh-9670

spring-boot-project/spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc

@@ -243,6 +243,7 @@ content into your application; rather pick only the properties that you need.
 	server.tomcat.protocol-header-https-value=https # Value of the protocol header that indicates that the incoming request uses SSL.
 	server.tomcat.redirect-context-root= # Whether requests to the context root should be redirected by appending a / to the path.
 	server.tomcat.remote-ip-header= # Name of the http header from which the remote ip is extracted. For instance `X-FORWARDED-FOR`
+	spring.tomcat.resource.cache-ttl=5000 # Time-to-live in milliseconds of the static resource cache.
 	server.tomcat.uri-encoding=UTF-8 # Character encoding to use to decode the URI.
 	server.undertow.accesslog.dir= # Undertow access log directory.
 	server.undertow.accesslog.enabled=false # Enable access log.