refactor(docker): update .dockerignore to remove .md and docs/

Remove markdown files and docs directory from Docker ignore.

Author: Akinator31

.dockerignore

@@ -9,9 +9,7 @@ target/
 **/Cargo.toml
 **/Cargo.lock
 
-*.md
 LICENSE
-docs/
 
 *.yml
 *.yaml
@@ -32,4 +30,4 @@ rustmail-*.tar.gz
 rustmail-*.zip
 
 tests/
-**/*_test.rs
+**/*_test.rs