docs: add documentation for the helmignore file

Signed-off-by: Ishaan Malhi <ishaan.malhi@gmail.com>

docs/README.md

@@ -15,6 +15,7 @@
 	- [Syncing your Chart Repository](chart_repository_sync_example.md)
 	- [Signing Charts](provenance.md)
 	- [Writing Tests for Charts](chart_tests.md)
+	- [Ignoring unwanted files and folders](helm_ignore_file.md)
 - [Chart Template Developer's Guide](chart_template_guide/index.md) - Master Helm templates
   - [Getting Started with Templates](chart_template_guide/getting_started.md)
   - [Built-in Objects](chart_template_guide/builtin_objects.md)

docs/helm_ignore_file.md

@@ -0,0 +1,23 @@
+# The .helmignore file
+
+The `.helmignore` file is used to specify files you don't want to include in your helm chart.
+
+If this file exists, the `helm package` command will ignore all the files that match the pattern specified in the `.helmignore` file while packaging your application.
+
+This can help in avoiding unncessary or sensitive files or directories from being added in your helm chart.
+
+The `.helmignore` file supports Unix shell glob matching, relative path matching, and negation (prefixed with !). Only one pattern per line is considered.
+
+Here is an example `.helmignore` file:
+
+```
+# comment
+.git
+*/temp*
+*/*/temp*
+temp?
+```
+
+**We'd love your help** making this document better. To add, correct, or remove
+information, [file an issue](https://github.com/helm/helm/issues) or
+send us a pull request.