Make a note for pip3 installations

[marcosflobo]

In case some users have python3-pip installed, the commands to install the opentelemetry-api & opentelemetry-sdk is pip3 instead of pip

Description

Please include a summary of the change and which issue is fixed. Please also include relevant motivation and context. List any dependencies that are required for this change.

Fixes # (issue)

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• Test A

Does This PR Require a Contrib Repo Change?

Answer the following question based on these examples of changes that would require a Contrib Repo Change:

• The OTel specification has changed which prompted this PR to update the method interfaces of opentelemetry-api/ or opentelemetry-sdk/

• The method interfaces of test/util have changed

• Scripts in scripts/ that were copied over to the Contrib repo have changed

• Configuration files that were copied over to the Contrib repo have changed (when consistency between repositories is applicable) such as in

  • pyproject.toml
  • isort.cfg
  • .flake8

• When a new .github/CODEOWNER is added

• Major changes to project information, such as in:

  • README.md
  • CONTRIBUTING.md

• Yes. - Link to PR:

• No.

Checklist:

• Followed the style guidelines of this project
• Changelogs have been updated
• Unit tests have been added
• Documentation has been updated

[linux-foundation-easycla]

The committers are authorized under a signed CLA.

• ✅ Marcos F. Lobo (42a6446)

[owais]

I don't think libraries should be educating people about package managers in general. User systems can be vastly different from a standard python installation and it'd be impractical to document for every scenario.

This change seems to be pretty harmless though so approving.

May be we can add a pitfalls or FAQ page to the documentation to mention all such edge cases when they come up.

[srikanthccv]

We have pip install ... in almost all the places across repo/docs and I believe regular user is knowledgeable enough to know and change the command themselves. pitfalls or FAQ page sounds like a good option to me.

[lzchen]

@owais @lonewolf3739
If we are going with the pitfalls/FAQ page then we probably shouldn't be moving forward with this change then correct? Otherwise we should include this excerpt in everywhere we are using pip install...

[srikanthccv]

@owais @lonewolf3739
If we are going with the pitfalls/FAQ page then we probably shouldn't be moving forward with this change then correct? Otherwise we should include this excerpt in everywhere we are using pip install...

Yes

[lzchen]

@marcosflobo
Does the above conversation make sense?

[ocelotl]

I appreciate the intention of this PR, but I agree that package installation details are outside the scope of this particular documentation. I suggest we close this PR.

[lzchen]

Closing in favor of #1875