feat(gatsby-source-filesystem): Added an 'ignore' property to the options to ignore more files. (#8016)

* feat(gatsby-source-filesystem): Added an 'ignore' property to the options to ignore more files.

* docs(gatsby-source-filesystem): Added an options section to the README and fixed an error in the example.

* update default list

Author: Mike-Dax

packages/gatsby-source-filesystem/README.md

@@ -35,12 +35,30 @@ module.exports = {
       options: {
         name: `data`,
         path: `${__dirname}/src/data/`,
+        ignore: [`**/\.*`], // ignore files starting with a dot
       },
     },
   ],
 }
 ```
 
+## Options
+
+In addition to the name and path parameters you may pass an optional `ignore` array of file globs to ignore.
+
+They will be added to the following default list:
+
+```
+**/*.un~
+**/.DS_Store
+**/.gitignore
+**/.npmignore
+**/.babelrc
+**/yarn.lock
+**/node_modules
+../**/dist/**
+```
+
 ## How to query
 
 You can query file nodes like the following:

packages/gatsby-source-filesystem/src/gatsby-node.js

@@ -136,6 +136,7 @@ See docs here - https://www.gatsbyjs.org/packages/gatsby-source-filesystem/
       `**/yarn.lock`,
       `**/node_modules`,
       `../**/dist/**`,
+      ...(pluginOptions.ignore || []),
     ],
   })