_content: in managing dependencies doc '-u' flag and mention '-modfile'

This CL is based on CL 648578 but without the modfile parts:

In the 'go tool' section, we remove the '-u' flag in 'go get -u tool',
which could be read as implying the '-u' is needed. This was previously
also an issue in the draft 1.24 release notes, which we addressed in
CL 638296.

Because many gophers persist in thinking the '-u' is required to upgrade
a target of 'go get', we also mention that 'go get tool' is equivalent
to 'go get tool@upgrade' to help people understand & internalize the
meaning of 'go get foo' with no @version suffix.

While we are here, s/acheive/achieve/.

For golang/go#48423
For golang/go#71663

Change-Id: I50d94b9d815e455f124f1790b13cc3b66a6a6964
Reviewed-on: https://go-review.googlesource.com/c/website/+/761140
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Michael Matloob <matloob@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
diff --git a/_content/doc/modules/managing-dependencies.md b/_content/doc/modules/managing-dependencies.md
index 957f31a..06c129f 100644
--- a/_content/doc/modules/managing-dependencies.md
+++ b/_content/doc/modules/managing-dependencies.md
@@ -534,9 +534,12 @@
 requirements that exist just to satisfy that tool dependency do not usually
 become requirements of your module.
 
-The `tool` [meta-pattern](/cmd/go#hdr-Package_lists_and_patterns) provides a way to perform operations on all tools simultaneously. For example you can upgrade all tools with `go get -u tool`, or install them all to $GOBIN with `go install tool`.
+The `tool` [meta-pattern](/cmd/go#hdr-Package_lists_and_patterns) provides a way to perform operations on all
+tools simultaneously. For example you can upgrade all tools with `go get tool`,
+which is equivalent to `go get tool@upgrade`, or install them all to $GOBIN
+with `go install tool`.
 
-In Go versions before 1.24, you can acheive something similar to a `tool`
+In Go versions before 1.24, you can achieve something similar to a `tool`
 directive by adding a blank import to a go file within the module that is
 excluded from the build using [build
 constraints](/pkg/go/build/#hdr-Build_Constraints). If you do this, you can then