Replace 2 broken links in README

[naltmann]

Link to https://developers.cloudflare.com/cloudflare-one/connections/connect-apps/configuration/private-networks is 404

[lazysegtree]

LGTM. Verified that old link doesn't works, and new one works. Thanks @naltmann

[lazysegtree]

@naltmann. There is one more dead link. Could you also fix that in this PR ?
Create a Tunnel with [these instructions](https://developers.cloudflare.com/cloudflare-one/connections/connect-apps/create-tunnel)
See - #1375

[lazysegtree]

Tagging you @chungthuang as you are active on this repo. This is a small fix in ReadMe for dead link. We dont need to delay to merge this.
If @naltmann is not actively looking at this anymore, we could create a separate PR. I could do that if you want.

[naltmann]

I think I was able to update the PR with the additional link fix.

[lazysegtree]

Thanks @naltmann. LGTM.

[jcsf]

Hi,
Thanks for your contribution but we don't accept typo's PR's because the cost of synchronizing our internal repo with the public one for a simple type is to high. We will just take all of them and batch the change into a single PR on our side.