Update ghost

Changes:

- https://github.com/docker-library/ghost/commit/18f90eb: Update to 2.31.0, ghost-cli 1.11.0
- https://github.com/docker-library/ghost/commit/d5eda0e: Update generated README

library/ghost

@@ -4,14 +4,14 @@ Maintainers: Tianon Gravi <[email protected]> (@tianon),
              Joseph Ferguson <[email protected]> (@yosifkit)
 GitRepo: https://github.com/docker-library/ghost.git
 
-Tags: 2.30.2, 2.30, 2, latest
+Tags: 2.31.0, 2.31, 2, latest
 Architectures: amd64, arm32v7, arm64v8, ppc64le, s390x
-GitCommit: 2a72c03e339bda5051b37edd0c553fe909e8408d
+GitCommit: 18f90eba6642edc3f11d988a745e458714b70ffa
 Directory: 2/debian
 
-Tags: 2.30.2-alpine, 2.30-alpine, 2-alpine, alpine
+Tags: 2.31.0-alpine, 2.31-alpine, 2-alpine, alpine
 Architectures: amd64, arm32v6, arm32v7, arm64v8, i386, ppc64le, s390x
-GitCommit: 2a72c03e339bda5051b37edd0c553fe909e8408d
+GitCommit: 18f90eba6642edc3f11d988a745e458714b70ffa
 Directory: 2/alpine
 
 Tags: 1.26.0, 1.26, 1