Feature Request: exclude from sitemap with frontmatter

[brianmercer]

Please consider adding a method to exclude pages from the sitemap through a frontmatter tag. i.e.

---
Title: Page That I Don't Want In the Sitemap
sitemap: false
---

[hi-kato]

This is nice idea.

Since I want to exclude "404. html", I would like to propose another method.

In proposal

add to Options

I thought it would be nice to add 「exclude」 to Options.

exclude:
  type: array
  required: false
  default: []
  example: 
    exclude:[
        '/404.html',
        '/hoge/'
    ]

Modify index.js

1. Add option(exclude) as follows in this part

     const {
       urls = [],
       hostname,
       cacheTime = 600,
       xslUrl,
       xmlNs,
       outFile = 'sitemap.xml',
       changefreq = 'daily',
   +   exclude = [],
       ...others
     } = options

2. Modify this part as follows

     pagesMap.forEach((page, url) => {
   -   sitemap.add({ url, ...page })
   +   if (!exclude.includes(url)) sitemap.add({ url, ...page })
     })

[ekoeryanto]

@hi-kato hit a PR, please

[dsturm]

Hey @ekoeryanto, would you please release a new version (to npm) for this new feature?

[ekoeryanto]

done