fix: highlight the required configuration and behavior of the fixer tools
The problem is that `hg help fix` didn't mention *how* to configure the tools,
and while I knew that `{rootpath}` existed in the configuration, I missed that
the tools require reading content from stdin. (I configured `gofmt` to use
`{rootpath}`, and that had the effect of squashing all changes in a file at `.`
into the first commit and emptying that content from its descendants.)
Basically all this does is put a pointer in the default (command level) help to
the extension level help that mentions the configuration, and moves the
extension level help that documents reading from stdin and writing to stdout to
the top to give it more prominence. The last sentence is adjusted a bit to
reflect the new location.
running: init test1
result: 0
running: add foo
result: 0
running: commit -m commit1 -d 2000-01-01 foo
result: 0
running: commit -m commit2 -d 2000-01-02 foo
result: 0
running: log -r 0
changeset: 0:0e4634943879
user: test
date: Sat Jan 01 00:00:00 2000 +0000
summary: commit1
result: 0
running: log -r tip
changeset: 1:45589e459b2e
tag: tip
user: test
date: Sun Jan 02 00:00:00 2000 +0000
summary: commit2
result: 0