We previously had this weak argument called projectName which let you
set a single part of a man page header. Instead do the best we can if
the caller doesn't pass us anything, but let the caller specify anything
they want.
The automatic Markdown generator works great!
But to use it to render the documentation in Hugo, we need front matter and slightly different links.
This commit adds optional callback funcs to add that.
An example from the kubernetes project, for the `kubectl config`
command, which as subcommands, and flags, and all sorts of stuff, it
will generate markdown like so:
config modifies .kubeconfig files
config modifies .kubeconfig files using subcommands like "kubectl config set current-context my-context"
```
kubectl config SUBCOMMAND
```
```
--envvar=false: use the .kubeconfig from $KUBECONFIG
--global=false: use the .kubeconfig from /home/username
-h, --help=false: help for config
--kubeconfig="": use a particular .kubeconfig file
--local=false: use the .kubeconfig in the current directory
```
```
--alsologtostderr=false: log to standard error as well as files
--api-version="": The API version to use when talking to the server
-a, --auth-path="": Path to the auth info file. If missing, prompt the user. Only used if using https.
--certificate-authority="": Path to a cert. file for the certificate authority.
--client-certificate="": Path to a client key file for TLS.
--client-key="": Path to a client key file for TLS.
--cluster="": The name of the kubeconfig cluster to use
--context="": The name of the kubeconfig context to use
--insecure-skip-tls-verify=false: If true, the server's certificate will not be checked for validity. This will make your HTTPS connections insecure.
--log_backtrace_at=:0: when logging hits line file:N, emit a stack trace
--log_dir=: If non-empty, write log files in this directory
--log_flush_frequency=5s: Maximum number of seconds between log flushes
--logtostderr=true: log to standard error instead of files
--match-server-version=false: Require server version to match client version
--namespace="": If present, the namespace scope for this CLI request.
--password="": Password for basic authentication to the API server.
-s, --server="": The address and port of the Kubernetes API server
--stderrthreshold=2: logs at or above this threshold go to stderr
--token="": Bearer token for authentication to the API server.
--user="": The name of the kubeconfig user to use
--username="": Username for basic authentication to the API server.
--v=0: log level for V logs
--validate=false: If true, use a schema to validate the input before sending it
--vmodule=: comma-separated list of pattern=N settings for file-filtered logging
```
* [kubectl](kubectl.md) - kubectl controls the Kubernetes cluster manager
* [kubectl config set](kubectl_config_set.md) - Sets an individual value in a .kubeconfig file
* [kubectl config set-cluster](kubectl_config_set-cluster.md) - Sets a cluster entry in .kubeconfig
* [kubectl config set-context](kubectl_config_set-context.md) - Sets a context entry in .kubeconfig
* [kubectl config set-credentials](kubectl_config_set-credentials.md) - Sets a user entry in .kubeconfig
* [kubectl config unset](kubectl_config_unset.md) - Unsets an individual value in a .kubeconfig file
* [kubectl config use-context](kubectl_config_use-context.md) - Sets the current-context in a .kubeconfig file
* [kubectl config view](kubectl_config_view.md) - displays merged .kubeconfig settings or a specified .kubeconfig file.
Eric Paris