Need better documentation on multiline support for `search` and `replace`

[fvosburgh]

I am attempting to perform version bumps against a maven project with a pom.xml file that has the project version and dependency versions. Sometimes, the project version will match up with the dependency version, and bumpversion will bump them both. The documentation clearly states that search and replace exist for this specific use case, however the Python format string documentation doesn't give me any information, as far as I can tell, to help me determine how to implement multi-line search and replace blocks. I've tried the following:

search = ""my
multiline
string""

search = my\nmultline\nstring

search = my{\n}multiline{\n}string

search = my
multiline
string

None of which have worked. It would be extremely helpful if the authors could create an example implementation of using search and replace with multiline strings.