docs(en): write introduction and getting-started pages

docs/en-US/getting-started/connection-parameters.md

@@ -1 +1,168 @@
 # Connection parameters
+
+Each protocol has its own set of authentication-form fields and its own
+command-line address syntax. This page describes them protocol by protocol.
+
+## SFTP / SCP
+
+Authentication-form fields:
+
+- Host (address)
+- Port (default `22`)
+- Username
+- Password or SSH key
+
+You can authenticate either with a username and password or with an SSH key.
+See [SSH key storage](../configuration/ssh-keys.md) for how to manage keys.
+
+Address syntax:
+
+```txt
+[protocol://][username@]<address>[:port][:wrkdir]
+```
+
+## FTP / FTPS
+
+Authentication-form fields:
+
+- Host (address)
+- Port (default `21`)
+- Username
+- Password
+- Secure (FTPS): enable TLS to use FTPS instead of plain FTP
+
+Address syntax:
+
+```txt
+[protocol://][username@]<address>[:port][:wrkdir]
+```
+
+## Kube
+
+Authentication-form fields:
+
+- Namespace
+- Cluster URL (Kubernetes API URL)
+- Username
+- Client certificate path
+- Client key path
+
+Address syntax:
+
+```txt
+kube://[namespace][@<cluster_url>][$</path>]
+```
+
+## S3
+
+termscp supports both AWS S3 and other S3-compatible endpoints.
+
+Authentication-form fields:
+
+- Bucket name
+- Region (for AWS S3) or endpoint (for other S3-compatible servers)
+- Profile
+- Access key
+- Secret access key
+- Security token
+- Session token
+- New path style
+
+The required and optional fields differ depending on the endpoint:
+
+- AWS S3:
+  - bucket name (required)
+  - region (required)
+  - profile (optional; defaults to `default`)
+  - access key (required unless the bucket is public)
+  - secret access key (required unless the bucket is public)
+  - security token (if required)
+  - session token (if required)
+  - new path style: NO
+- Other S3 endpoints:
+  - bucket name (required)
+  - endpoint (required)
+  - access key (required unless the bucket is public)
+  - secret access key (required unless the bucket is public)
+  - new path style: YES
+
+Address syntax:
+
+```txt
+s3://<bucket>@<region>[:profile][:/wrkdir]
+```
+
+For example:
+
+```txt
+s3://buckethead@eu-central-1:default:/assets
+```
+
+### S3 credentials
+
+To connect to an AWS S3 bucket you must provide credentials. There are three
+ways to do this.
+
+1. Authentication form: provide the access key (usually mandatory), the secret
+   access key (usually mandatory), the security token, and the session token.
+   If you save the S3 connection as a bookmark, the access key and secret access
+   key are saved as an encrypted AES-256/BASE64 string in your bookmarks file.
+   The security token and session token are not saved, since they are meant to
+   be temporary credentials.
+2. Credentials file: configure the AWS CLI with `aws configure`. Your
+   credentials are then stored at `~/.aws/credentials`. If you use a profile
+   other than `default`, provide it in the profile field of the authentication
+   form.
+3. Environment variables: provide your credentials as environment variables.
+   These always override the credentials in the credentials file. The following
+   are usually mandatory:
+
+   - `AWS_ACCESS_KEY_ID`: AWS access key ID (usually starts with `AKIA...`)
+   - `AWS_SECRET_ACCESS_KEY`: the secret access key
+
+   If you have configured stronger security, you may also need:
+
+   - `AWS_SECURITY_TOKEN`: security token
+   - `AWS_SESSION_TOKEN`: session token
+
+Your credentials are safe: termscp does not manipulate these values directly.
+They are consumed directly by the `s3` crate.
+
+## SMB
+
+Authentication-form fields:
+
+- Server (address)
+- Share
+- Username
+- Password
+- Port (other systems only; default `445`)
+- Workgroup (other systems only)
+
+On Windows the port and workgroup fields are not used.
+
+Windows address syntax:
+
+```txt
+\\[username@]<server-name>\<share>[\path\...]
+```
+
+Other systems address syntax:
+
+```txt
+smb://[username@]<server-name>[:port]/<share>[/path/.../]
+```
+
+## WebDAV
+
+Authentication-form fields:
+
+- URI (the base WebDAV endpoint)
+- Username
+- Password
+
+Address syntax:
+
+```txt
+http(s)://<username>:<password>@<url></path>
+```