Fix a typo

Author: mhauru

developers/contributing/index.qmd

@@ -55,7 +55,8 @@ We merge all code changes through pull requests on GitHub.
 To make a contribution to one of the Turing packages, fork it on GitHub, start a new branch on your fork, and add commits to it.
 Once you're done, open a pull request to the main repository under [TuringLang](https://github.com/TuringLang).
 Someone from the dev team will review your code (if they don't, ping `@TuringLang/maintainers` in a comment to get their attention) and check that the continuous integration tests pass (with some allowed exceptions, see below).
-If all looks good, we'll merge your PR with much joy and gratitude If not, we'll help you fix it and then merge it with much joy and gratitude
+If all looks good, we'll merge your PR with much joy and gratitude.
+If not, we'll help you fix it and then merge it with much joy and gratitude
 
 Everything in this section about pull requests and branches applies to the Turing.jl and DynamicPPL.jl repositories.
 Most of it also applies to other repositories under the TuringLang ecosystem, though some do not bother with the `main`/`breaking` distinction or with a `HISTORY.md`.