docs(dependency pinning): better alt text for images (#29350)

docs/usage/dependency-pinning.md

@@ -142,7 +142,7 @@ You can add a package rule in our Renovate configuration to group these together
 Since both `yarn` and `npm@5` both support lock files, it's a common question to ask "Why should I pin dependencies if I'm already using a lock file?".
 It's a good question!
 
-![broken-lockfile](assets/images/broken-lockfile.jpg){ loading=lazy }
+![A scary bald man in a subway carriage, surrounded with this text: when your dependencies are broken but you still got a lockfile](assets/images/broken-lockfile.jpg){ loading=lazy }
 
 Lock files are a great companion to SemVer ranges _or_ pinning dependencies, because these files lock (pin) deeper into your dependency tree than you see in `package.json`.
 
@@ -158,7 +158,7 @@ If a lock file gets out of sync with its `package.json`, it can no longer be gua
 
 The lock file has only delayed the inevitable problem, and provides much less visibility than `package.json`, because it's not designed to be human readable and is quite dense.
 
-![all-dead](assets/images/all-dead.jpg){ loading=lazy }
+![Man with goth-style hair and makeup saying: They're all dead. They just don't know it yet.](assets/images/all-dead.jpg){ loading=lazy }
 
 If the `package.json` has a range, and a new in-range version is released that would break the build, then essentially your `package.json` is in a state of "broken", even if the lock file is still holding things together.