docs: Update CONTRIBUTING.md with argo auth token command fix.

[NikeNano]

The current suggested way to get the auth token for argo when deployed don't seam to work. This PR contains a fix where:

./dist/argo auth token

is suggested to replace

./dist/argo token

Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this is a chore.
• The title of the PR is (a) conventional, (b) states what changed, and (c) suffixes the related issues number. E.g. "fix(controller): Updates such and such. Fixes #1234".
• I have written unit and/or e2e tests for my change. PRs without these are unlike to be merged.
• Optional. I've added My organization is added to the USERS.md.
• I've signed the CLA and required builds are green.

[codecov]

Codecov Report

Merging #2410 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2410   +/-   ##
=======================================
  Coverage   13.13%   13.13%           
=======================================
  Files          72       72           
  Lines       25084    25084           
=======================================
  Hits         3294     3294           
  Misses      21375    21375           
  Partials      415      415

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[alexec]

Good spot!