feat: specify --init filename/path

[HeCorr]

Closes #2008.

Task currently does not provide a way to specify which filename to use when initializing a file (hardcoded as Taskfile.yml), forcing users to rename the file/extension after creation.

This PR fixes that by taking the target filename from the first non-flag argument:

$ task --init tasks.yml
Taskfile created: tasks.yml

If a path with no name (extension only) is provided, the default name "Taskfile" is prepended to it:

$ task --init .yaml
Taskfile created: Taskfile.yaml

Different directories are also supported:

$ task --init sub/NotMakefile.yml
Taskfile created: sub/NotMakefile.yml

$ task --init sub/.yaml
Taskfile created: sub/Taskfile.yaml

This PR also includes the following updates to the docs:

• Fixed the Flags header being inside the Tip admonition in CLI Reference page:

• Updated the --taskfile flag information:

[pd93]

Thanks for this! Generally supportive of this improvement. Just a couple of discussion points on the implementation/docs.

[vmaerten]

@pd93 not sure why TestInit is failing now. It didn't fail in #2011, did it?

It didn't. It fails because, previously in the test, we passed the directory containing the Taskfile as the second parameter, and we concatenated the filename in the InitTaskfile method.
Now, the concatenation has been removed, os.stat is performed on the directory itself, and it already exists
It prevents the InitTaskfile to override existing file.

(see :

task/init_test.go

Line 23 in 23df1f0

if err := task.InitTaskfile(io.Discard, dir); err != nil {

and https://github.com/go-task/task/pull/2018/files#diff-09d6aefefdc39400d949bac4606f951988cbe618740e96ecfee50236859da58bR26-R32)

[HeCorr]

oh, oops. I must have messed up the merge then. thanks.

[HeCorr]

Refactor complete, main post updated, manual tests passing, ready to remove Draft status.

Tested commands:

Command	Result
task --init	Taskfile created: Taskfile.yml
task --init tasks.yml	Taskfile created: tasks.yml
task --init .yaml	Taskfile created: Taskfile.yaml
task --init sub/	Taskfile created: sub/Taskfile.yml
task --init sub/tasks.yml	Taskfile created: sub/tasks.yml
task --init sub/.yaml	Taskfile created: sub/Taskfile.yaml

[HeCorr]

Modified InitTaskfile() to return the final calculated file path as suggested, which was honestly the right call as that may also help with error handling in case initialization fails.

Only a small quirk with the current implementation which prints the path relative to the current dir is that this may be printed depending on the input path:

$ task --init ~/Desktop
Taskfile created: ../../../../../../Desktop/Taskfile.yml

...but it is generally much shorter:

$ task --init
Taskfile created: Taskfile.yml

[HeCorr]

Updated the docs one last time as well as the original PR message.