Update PULL_REQUEST_TEMPLATE.md

to refer to develop.toml now

Author: mjr-deltares

.github/PULL_REQUEST_TEMPLATE.md

@@ -11,8 +11,8 @@ Checklist of items for pull request
 - [ ] Added doxygen comments to new and modified procedures
 - [ ] Updated meson files, makefiles, and Visual Studio project files for new source files
 - [ ] Updated [definition files](/MODFLOW-ORG/modflow6/tree/develop/doc/mf6io/mf6ivar)
-- [ ] Updated [develop.tex](/MODFLOW-ORG/modflow6/doc/ReleaseNotes/develop.tex) with a plain-language description of the bug fix, change, feature; required for changes that may affect users
+- [ ] Updated [develop.toml](/MODFLOW-ORG/modflow6/doc/ReleaseNotes/develop.toml) with a plain-language description of the bug fix, change, feature; required for changes that may affect users
 - [ ] Updated [input and output guide](/MODFLOW-ORG/modflow6/doc/mf6io)
 - [ ] Removed checklist items not relevant to this pull request
 
-For additional information see [instructions for contributing](/MODFLOW-ORG/modflow6/.github/CONTRIBUTING.md) and [instructions for developing](/MODFLOW-ORG/modflow6/.github/DEVELOPER.md).
+For additional information see [instructions for contributing](/MODFLOW-ORG/modflow6/.github/CONTRIBUTING.md) and [instructions for developing](/MODFLOW-ORG/modflow6/.github/DEVELOPER.md).