Update of docs

[jynolen]

Hello.

I'm trying to develop a new provider following this page:

Adding a new DNS provider

Basically for now I just Copy route53.py to src/lexicon/providers/foo.py and I expect that running lexicon it brings me the "foo" provider. But not seems to works

walkthough

git clone https://github.com/AnalogJ/lexicon.git
cp lexicon/src/lexicon/_private/providers/route53.py lexicon/src/lexicon/providers/foo.py
poetry install -E full
source .venv/bin/activate
lexicon foo

Error was:

lexicon foo
usage: lexicon [-h] [--version] [--delegated DELEGATED] [--config-dir CONFIG_DIR] [--resolve-zone-name]
               {aliyun,aurora,auto,azure,cloudflare,cloudns,cloudxns,conoha,constellix,ddns,digitalocean,dinahosting,directadmin,dnsimple,dnsmadeeasy,dnspark,dnspod,dnsservices,dreamhost,duckdns,dynu,easydns,easyname,euserv,exoscale,flexibleengine,gandi,gehirn,glesys,godaddy,googleclouddns,gransy,gratisdns,henet,hetzner,hostingde,hover,infoblox,infomaniak,internetbs,inwx,joker,linode,linode4,localzone,luadns,memset,misaka,mythicbeasts,namecheap,namecom,namesilo,netcup,nfsn,njalla,nsone,oci,onapp,online,ovh,plesk,pointhq,porkbun,powerdns,rackspace,rage4,rcodezero,route53,safedns,sakuracloud,softlayer,timeweb,transip,ultradns,valuedomain,vercel,vultr,webgo,wedos,yandex,yandexcloud,zeit,zilore,zonomi}
               ...
lexicon: error: argument provider_name: invalid choice: 'foo' (choose from 'aliyun', 'aurora', 'auto', 'azure', 'cloudflare', 'cloudns', 'cloudxns', 'conoha', 'constellix', 'ddns', 'digitalocean', 'dinahosting', 'directadmin', 'dnsimple', 'dnsmadeeasy', 'dnspark', 'dnspod', 'dnsservices', 'dreamhost', 'duckdns', 'dynu', 'easydns', 'easyname', 'euserv', 'exoscale', 'flexibleengine', 'gandi', 'gehirn', 'glesys', 'godaddy', 'googleclouddns', 'gransy', 'gratisdns', 'henet', 'hetzner', 'hostingde', 'hover', 'infoblox', 'infomaniak', 'internetbs', 'inwx', 'joker', 'linode', 'linode4', 'localzone', 'luadns', 'memset', 'misaka', 'mythicbeasts', 'namecheap', 'namecom', 'namesilo', 'netcup', 'nfsn', 'njalla', 'nsone', 'oci', 'onapp', 'online', 'ovh', 'plesk', 'pointhq', 'porkbun', 'powerdns', 'rackspace', 'rage4', 'rcodezero', 'route53', 'safedns', 'sakuracloud', 'softlayer', 'timeweb', 'transip', 'ultradns', 'valuedomain', 'vercel', 'vultr', 'webgo', 'wedos', 'yandex', 'yandexcloud', 'zeit', 'zilore', 'zonomi')