rustup: update page, rustup-{show,update,check,default,toolchain,target}: add page (#10642)

pages/common/rustup-target.md

@@ -0,0 +1,21 @@
+# rustup target
+
+> Modify a toolchain's supported targets.
+> Without the `--toolchain` option `rustup` will use the default toolchain. See `rustup help toolchain` for more information about toolchains.
+> More information: <https://rust-lang.github.io/rustup>.
+
+- Add a target to a toolchain:
+
+`rustup target add --toolchain {{toolchain}} {{target}}`
+
+- Remove a target from a toolchain:
+
+`rustup target remove --toolchain {{toolchain}} {{target}}`
+
+- List available and installed targets for a toolchain:
+
+`rustup target list --toolchain {{toolchain}}`
+
+- List installed targets for a toolchain:
+
+`rustup target list --toolchain {{toolchain}} --installed`