dnsapi support for HestiaCP

[radumalica]

This adds dnsapi support for HestiaCP control panel.

There are some prerequisites before trying to use this dns api script:

Log in to HestiaCP panel as admin or user
Go to Server -> Configure -> API if logged in as admin otherwise if a normal user, click on your profile on top right, and click Access Keys on the upper menu above "Edit User" field
Choose update-dns-records as Access key role
Copy Host, Access Key, and Secret Key
Login to our HestiaCP server as root, and go to /usr/local/hestia/data/api
The file "update-dns-records" should contain this line in order for this script to work:
ROLE='user'
COMMANDS='v-list-dns-records,v-change-dns-record,v-delete-dns-record,v-add-dns-record'
By default, only v-list-dns-records and v-change-dns-record are enabled.
export these variables in your shell or add them in a file and source them.

export HESTIA_HOST="https://panel.domain.com:8083"
export HESTIA_ACCESS="your_access_key"
export HESTIA_SECRET="your_secret_key"
export HESTIA_USER="your_username"

NOTES:

for wildcard certificates to work, you need to use LetsEncrypt V2 provider, not Alpha ZeroSSL which is default in acme.sh
domains available for requesting SSL certificates will be the ones defined under your HestiaCP username (HESTIA_USER).
Issues:

DNS test is successful but your Github actions randomly fails on docker acmetest in the middle of acme.sh processing stuff.

[github-actions]

Welcome
First thing: don't send PR to the master branch, please send to the dev branch instead.
Please make sure you've read our DNS API Dev Guide and DNS-API-Test.
Then reply on this message, otherwise, your code will not be reviewed or merged.
Please also make sure to add/update the usage here: https://github.com/acmesh-official/acme.sh/wiki/dnsapi2
We look forward to reviewing your Pull request shortly ✨
注意: 必须通过了 DNS-API-Test 才会被 review. 无论是修改, 还是新加的 dns api, 都必须确保通过这个测试.

[radumalica]

Added link and content to the documentation.
The test for DNS runs on Docker first, it creates certificates correctly, but the action fails randomly in the middle of processing data.