Fix contrib package versions

[grauwoelfchen]

Hello,

I just noticed that the version numbers of some contrib packages on the master branch are older than the latest versions actually released on on crates.io, while the v0.5 branch already has the correct values.

I understand that the master branch contains unpublished changes (like dependencies etc.), but I was a bit confused by these relapse differences when reading the code at a glance 😅

Changes

To catch up with the latest versions, I've updated the values in each Cargo.toml (and also docs/guide, doc comments and each README.md, according to the changes in the v0.5 branch) as follows:

contrib	version
rocket_db_pools	0.1.0 -> 0.2.0
rocket_db_pools_codegen	0.1.0 -> 0.2.0
rocket_dyn_templates	0.1.0 -> 0.2.0
rocket_ws	0.1.0 -> 0.1.1

When the next version (0.6?) is released, these values perhaps may be different. But until then, I hope these changes make sense and avoid any misunderstanding 🙆🏽‍♀️