feat: supports the default command fallback when command not found ( resolved #277 )

[snowyu]

add an alias 'default' to set a default command.

[salesforce-cla]

Thanks for the contribution! Before we can merge this, we need @snowyu to sign the Salesforce.com Contributor License Agreement.

[codecov]

Codecov Report

Merging #139 into master will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff           @@
##           master    #139   +/-   ##
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  Coverage    0.00%   0.00%           
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  Files           2       2           
  Lines          12      12           
  Branches        3       3           
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  Misses         12      12           

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[RasPhilCo]

You should do this with the command_not_found hook https://oclif.io/docs/hooks

[snowyu]

command_not_found can not do this operation unless it accepts a new command return and do not throw exception:

    if (!c) {
		      await this.runHook('command_not_found', {id})
		      throw new CLIError(`command ${id} not found`)

[RasPhilCo]

You are correct, I misread earlier. See my comment oclif/oclif#277 (comment) on adding a root index command. Thanks for the PR on this! I really don't like to not use your efforts, but this particular solution was an edge case that was easier for me to write than explain.