Update docs

NEWS.md

@@ -4,7 +4,7 @@
 
 - The behavior previously implemented via the `output =` and `ts =` arguments of `slim()` (and `msprime()`) has been changed to facilitate more straightforward handling of output paths in user-defined SLiM extensions and other packages leveraging _slendr_ for inference. The `slim()` and `msprime()` function interfaces are now simplified in the following way:
 
-  - `slim()`: the `ts` argument is now logical. `TRUE` switches on tree-sequence recording, `FALSE` switches it off. If tree-sequence recording is on, the function automatically returns a tree-sequence R object. If users want to save it to a custom location, they should use the function `ts_save()` on the returned tree-sequence object. If customized output files are to be produced via user-defined extension scripts, those scripts can use a _slendr_/SLiM constant `PATH`, which is always available in the built-in SLiM script and which can be set from R via `slim(..., path = <path to a directory>)`. In that case, the `slim()` function always returns that path back. Crucially, in this case `slim()` will not return a tree sequence object, but that object can be loaded by `ts_load("<path to a directory>/slim.trees")`. In other words, nothing changes for the usual SLiM-based _slendr_ workflow, but for models generating custom output files, a small amount of work is needed to load the tree sequence -- the tree-sequence file outputs are therefore treated exactly the same way as non-tree-sequence user-defined output files. As a result of these changes, `slim()` no longer accepts a `load = TRUE|FALSE` argument.
+  - `slim()`: the `ts` argument is now logical. `TRUE` switches on tree-sequence recording, `FALSE` switches it off. If tree-sequence recording is on (the default setting), the function automatically returns a tree-sequence R object. If users want to save it to a custom location, they should use the function `ts_save()` on the returned tree-sequence object. If customized output files are to be produced via user-defined extension scripts, those scripts can use a _slendr_/SLiM constant `PATH`, which is always available in the built-in SLiM script and which can be set from R via `slim(..., path = <path to a directory>)`. In that case, the `slim()` function always returns that path back. Crucially, in this case `slim()` will not return a tree sequence object, but that object can be loaded by `ts_load("<path to a directory>/slim.trees")`. In other words, nothing changes for the usual SLiM-based _slendr_ workflow, but for models generating custom output files, a small amount of work is needed to load the tree sequence -- the tree-sequence file outputs are therefore treated exactly the same way as non-tree-sequence user-defined output files. As a result of these changes, `slim()` no longer accepts a `load = TRUE|FALSE` argument.
 
 The above is implemented in PR [#157](https://github.com/bodkan/slendr/pull/157).