text/template: documentation: "pipeline" is never defined clearly

[bprosnitz]

Referring to: https://golang.org/pkg/text/template/

In the "action" section it says:

Here is the list of actions. "Arguments" and "pipelines" are evaluations of data, defined in detail below.

and later

{{pipeline}}
    The default textual representation of the value of the pipeline
    is copied to the output.

in the pipeline section it says

Pipelines

A pipeline may be "chained" by separating a sequence of commands with pipeline characters '|'. In a chained pipeline, the result of the each command is passed as the last argument of the following command. The output of the final command in the pipeline is the value of the pipeline.

The output of a command will be either one value or two values, the second of which has type error. If that second value is present and evaluates to non-nil, execution terminates and the error is returned to the caller of Execute.

From this, it sounds like a pipeline is the result of a command but it is not stated clearly. The first sentence of the pipelines section should start off with a definition of what it is.

[bradfitz]

I've never been a big template user but on the rare occasions where I do use the package, I immediately re-read the docs and have also been often confused by this.

/cc @robpike @adg

[gopherbot]

CL https://golang.org/cl/18775 mentions this issue.