Adding newline(s) after header (#29)

* Update to eslint 7.7.0
* Add a third option to specify number of linebreaks after the header.

.travis.yml

@@ -1,4 +1,3 @@
 language: node_js
 node_js:
-  - "8"
-  - "10"
+  - "14"

README.md

@@ -7,7 +7,7 @@ Often you will want to have a copyright notice at the top of every file. This ES
 
 ## Usage
 
-This rule takes 1 or 2 arguments with an optional settings object.
+This rule takes 1, 2 or 3 arguments with an optional settings object.
 
 ### 1 argument
 
@@ -48,6 +48,61 @@ In the 2 argument form the first must be either `"block"` or `"line"` to indicat
 }
 ```
 
+### 3 arguments
+
+The optional third argument which defaults to 1 specifies the number of newlines that are enforced after the header.
+
+Zero newlines:
+```json
+{
+    "plugins": [
+        "header"
+    ],
+    "rules": {
+        "header/header": [2, "block", [" Copyright now","My Company "], 0]
+    }
+}
+```
+```js
+/* Copyright now
+My Company */ console.log(1)
+```
+
+One newline (default)
+```json
+{
+    "plugins": [
+        "header"
+    ],
+    "rules": {
+        "header/header": [2, "block", [" Copyright now","My Company "], 1]
+    }
+}
+```
+```js
+/* Copyright now
+My Company */
+console.log(1)
+```
+
+two newlines
+```json
+{
+    "plugins": [
+        "header"
+    ],
+    "rules": {
+        "header/header": [2, "block", [" Copyright now","My Company "], 2]
+    }
+}
+```
+```js
+/* Copyright now
+My Company */
+
+console.log(1)
+```
+
 #### Regular expressions
 
 Instead of a string to be checked for exact matching you can also supply a regular expression. Be aware that you have to escape backslashes: