Fix mentions of Open Location Code and plus codes

[fulldecent]

This updates mentions of "Open Location Codes" "Plus Codes" and other errors in this repo to instead properly refer to:

1. Mention "Open Location Code" the project, library and API; and
2. Mention "plus codes" referring to the generated codes.

This fixes issue #431.

---

This also fixes a reference to the old URL openlocationcode.com to instead go to its new URL, which I hope is in scope for these name changes.

[drinckes]

For future reference, this PR is on the big side. It's better to send multiple small PRs that can be reviewed/approved/merged quickly, rather than large ones.

[fulldecent]

Got it.

There's only five words in this PR, just many occurrences of those five words. Would you like me to split up this PR for some of the files separately?

[fulldecent]

Todo:

• Update "plus code" -> "Plus Code" because

  open-location-code/Documentation/Specification/Naming_Guidelines.md

  Lines 11 to 20 in 4d83aed

  	## Plus Codes
  	When referring to Plus Codes in English, the **only** term that should be used is "Plus Code", in Title Case.
  	Some examples of usage are:
  	* "My Plus Code is CX37+M9."
  	* "I gave your Plus Code to the cab driver and he found the way without any problems."
  	* "Will the postcard arrive if I put your Plus Code as the address?"
  	* "Enter your Plus Code or street address here."

[drinckes]

You've got a formatting failure in the Java source.

[fulldecent]

Thanks for the review. This PR is rebased, removes formatting changes and standardizes on "Plus Codes" and "Open Location Code" as per specification at

open-location-code/Documentation/Specification/Naming_Guidelines.md

Lines 11 to 20 in 4d83aed

	## Plus Codes
	When referring to Plus Codes in English, the **only** term that should be used is "Plus Code", in Title Case.
	Some examples of usage are:
	* "My Plus Code is CX37+M9."
	* "I gave your Plus Code to the cab driver and he found the way without any problems."
	* "Will the postcard arrive if I put your Plus Code as the address?"
	* "Enter your Plus Code or street address here."

[drinckes]

Thanks for helping to clean up the documentation!

[drinckes]

lol merge first then close