Auto merge of #14540 - RalfJung:docs-target, r=weihanglo

docs: Feature resolver version 2: clarify use of 'target'

IIUC, these two uses of the word `target` right next to each other in the docs actually have different meaning. That is kind of confusing, so add disambiguators and links to the glossary that should help clarify this.

Author: bors

src/doc/src/reference/features.md

@@ -365,11 +365,11 @@ that unification can be unwanted. The exact situations are described in the
 [resolver chapter][resolver-v2], but in short, it avoids unifying in these
 situations:
 
-* Features enabled on [platform-specific dependencies] for targets not
+* Features enabled on [platform-specific dependencies] for [target architectures][target] not
   currently being built are ignored.
 * [Build-dependencies] and proc-macros do not share features with normal
   dependencies.
-* [Dev-dependencies] do not activate features unless building a target that
+* [Dev-dependencies] do not activate features unless building a [Cargo target][target] that
   needs them (like tests or examples).
 
 Avoiding the unification is necessary for some situations. For example, if a
@@ -393,6 +393,8 @@ the resolved features. For build dependencies, this is not necessary if you
 are cross-compiling with the `--target` flag because build dependencies are
 always built separately from normal dependencies in that scenario.
 
+[target]: ../appendix/glossary.md#target
+
 ### Resolver version 2 command-line flags
 
 The `resolver = "2"` setting also changes the behavior of the `--features` and