[skip changelog] Fix incorrect software specificity/non-specificity in documentation

[per1234]

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• The PR has no duplicates (please search among the Pull Requests before creating one)
• The PR follows our contributing guidelines

• What kind of change does this PR introduce?
  docs update

• What is the current behavior?

The documentation imported from the arduino/Arduino wiki was mostly written when Arduino's only official development software was the Arduino IDE. This resulted in many statements that mentioned the Arduino IDE specifically, when they actually apply to other development software as well. Conversely, there were Arduino-IDE specific statements which were not qualified as such.

• Does this PR introduce a breaking change?

No

• Other information:

I've used the term "Arduino development software" in documentation that applies to Arduino IDE, Arduino Pro IDE, Arduino Web Editor, and Arduino CLI all.

In the Sketch build process document, it used the term "Arduino environment" three times in the introductory text, which I replaced because I wanted a consistent term throughout the documentation and "Arduino environment" seemed more vague, but if you prefer I could change all instances of "Arduino development software" to "Arduino environment" instead.

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I used the term "IDE" or "IDEs" in documentation that applies to Arduino IDE, Arduino Pro IDE and Arduino Web Editor all, but not to Arduino CLI.

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I wasn't sure about this line:

arduino-cli/docs/package_index_json-specification.md

Line 202 in c076ad3

The `version` field is validated by both Arduino IDE and [JSemVer](https://github.com/zafarkhaja/jsemver). Here are the rules Arduino IDE follows for parsing versions ([source](https://github.com/arduino/Arduino/blob/master/arduino-core/src/cc/arduino/contributions/VersionHelper.java)):

The version field is validated by both Arduino IDE and JSemVer. Here are the rules Arduino IDE follows for parsing versions (source):

• Split the version at the - character and continue with the first part.
• If there are no dots (.), parse version as an integer and form a Version from that integer using Version.forIntegers
• If there is one dot, split version into two, parse each part as an integer, and form a Version from those integers using Version.forIntegers
• Otherwise, simply parse version into a Version using Version.valueOf

Can this be changed to:

The version field is validated by the Arduino development software:
...

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Fixes #616 (review)