[manifest] Clarify "scope" in step #3 of Section 3 (#320)

Step #3 in Section 3 says

[[
3. If target is same origin as scope and target's pathname starts with scope's pathname, return true.
]]

The term "scope" is used twice in that sentence and since it is not explicitly qualified, its meaning is unclear to me. Since "scope" is italicized (via <var>), it seems like it could be a variable (but there is no explicit "scope" variable) or perhaps it is "scopeURL", or perhaps "navigation scope" or maybe something else?

(My advanced apologies if I'm simply mis-reading this sentence.)

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Reply to this email directly or view it on GitHub:
https://github.com/w3c/manifest/issues/320