make DocFooter more flexible, add to swagger template

src/components/DocFooter.jsx

@@ -4,31 +4,31 @@ import { ReactComponent as Pencil } from '../images/pencil.svg'
 import styles from './DocFooter.module.scss'
 import { githubContentPath, githubDevOceanPath } from '../../config'
 
-const DocFooter = ({ post }) => {
-    const { sourceInstanceName } = post.parent
-
+const DocFooter = ({ post, url, externalName }) => {
     let path
-    let externalRepoName
+
+    if (post) {
+        const { sourceInstanceName } = post.parent
 
         switch (sourceInstanceName) {
             case 'dev-ocean':
                 path = githubDevOceanPath
-            externalRepoName = sourceInstanceName
+                externalName = sourceInstanceName
                 break
             default:
                 path = githubContentPath
         }
 
+        url = `${path}/${post.parent.relativePath}`
+    }
+
     return (
         <footer className={styles.footer}>
-            <a
-                href={`${path}/${post.parent.relativePath}`}
-                className={!post.html ? styles.active : null}
-            >
+            <a href={url} className={post && !post.html ? styles.active : null}>
                 <Pencil /> Edit this page on GitHub
-                {externalRepoName && (
+                {externalName && (
                     <span className={styles.externalRepoName}>
-                        {externalRepoName}
+                        {externalName}
                     </span>
                 )}
             </a>
@@ -37,7 +37,9 @@ const DocFooter = ({ post }) => {
 }
 
 DocFooter.propTypes = {
-    post: PropTypes.object.isRequired
+    post: PropTypes.object,
+    url: PropTypes.string,
+    externalName: PropTypes.string
 }
 
 export default DocFooter

src/templates/ApiSwagger.jsx

@@ -8,6 +8,7 @@ import Content from '../components/Content'
 import HeaderSection from '../components/HeaderSection'
 import Sidebar from '../components/Sidebar'
 import DocHeader from '../components/DocHeader'
+import DocFooter from '../components/DocFooter'
 import SEO from '../components/Seo'
 import stylesDoc from './Doc.module.scss'
 import styles from './ApiSwagger.module.scss'
@@ -275,6 +276,11 @@ export default class ApiSwaggerTemplate extends Component {
                                 )}
 
                                 <Paths paths={paths} />
+
+                                <DocFooter
+                                    url={`https://github.com/oceanprotocol/${title.toLowerCase()}`}
+                                    externalName={`${title} Swagger spec`}
+                                />
                             </article>
                         </main>
                     </Content>