Add a note about sourceignore recursion

Signed-off-by: Kingdon Barrett <kingdon@weave.works>

Author: Kingdon Barrett

docs/spec/v1beta2/gitrepositories.md

@@ -487,6 +487,9 @@ repository. The `.sourceignore` file follows [the `.gitignore` pattern
 format](https://git-scm.com/docs/gitignore#_pattern_format), and
 pattern entries may overrule [default exclusions](#default-exclusions).
 
+The controller recursively loads ignore files so a `.sourceignore` can be
+placed in the repository root or in subdirectories.
+
 #### Ignore spec
 
 Another option is to define the exclusions within the GitRepository spec, using

docs/spec/v1beta2/ocirepositories.md

@@ -526,6 +526,16 @@ spec:
     /deploy/**/*.txt
 ```
 
+#### `.sourceignore` file
+
+Excluding files is possible by adding a `.sourceignore` file in the artifact.
+The `.sourceignore` file follows [the `.gitignore` pattern
+format](https://git-scm.com/docs/gitignore#_pattern_format), and pattern
+entries may overrule [default exclusions](#default-exclusions).
+
+The controller recursively loads ignore files so a `.sourceignore` can be
+placed in the artifact root or in subdirectories.
+
 ### Triggering a reconcile
 
 To manually tell the source-controller to reconcile a OCIRepository outside the