Add directories input (#8)

Co-authored-by: Sascha Mann <git@mail.saschamann.eu>
Co-authored-by: Michael Schlottke-Lakemper <michael@sloede.com>

README.md

@@ -13,3 +13,24 @@ See [PkgTemplates.jl](https://github.com/invenia/PkgTemplates.jl/blob/master/tes
         with:
           file: lcov.info
 ```
+
+One can also specify the directory or directories to use via the `directories` input (which defaults to `src`). E.g.
+```yaml
+
+      - uses: julia-actions/julia-processcoverage@v1
+        with:
+          directories: src,examples
+      - uses: codecov/codecov-action@v1
+        with:
+          file: lcov.info
+```
+instructs the action to look for coverage information in both `src` and an `examples` folder. Likewise, use
+```yaml
+      - uses: julia-actions/julia-processcoverage@v1
+        with:
+          directories: path/to/subdir/package/src
+      - uses: codecov/codecov-action@v1
+        with:
+          file: lcov.info
+```
+to get coverage information from a package in a subdirectory of the repo.