fix(docs): add caching docs to exec, init

fix grammar on caching docs for search

PR-URL: #2542
Credit: @wraithgar
Close: #2542
Reviewed-by: @ruyadorno

Author: wraithgar

docs/content/commands/npm-exec.md

@@ -173,6 +173,28 @@ This resulted in some shifts in its functionality:
 - The `--shell` option is replaced with `--script-shell`, but maintained
   in the `npx` executable for backwards compatibility.
 
+### A note on caching
+
+The npm cli utilizes its internal package cache when using the package
+name specified.  You can use the following to change how and when the
+cli uses this cache. See [`npm cache`](/commands/npm-cache) for more on
+how the cache works.
+
+#### prefer-online
+
+Forces staleness checks for packages, making the cli look for updates
+immediately even if the package is already in the cache.
+
+#### prefer-offline
+
+Bypasses staleness checks for packages.  Missing data will still be
+requested from the server. To force full offline mode, use `offline`.
+
+#### offline
+
+Forces full offline mode. Any packages not locally cached will result in
+an error.
+
 ### See Also
 
 * [npm run-script](/commands/npm-run-script)

docs/content/commands/npm-init.md

@@ -71,9 +71,32 @@ Generate it without having it ask any questions:
 $ npm init -y
 ```
 
+### A note on caching
+
+The npm cli utilizes its internal package cache when using the package
+name specified.  You can use the following to change how and when the
+cli uses this cache. See [`npm cache`](/commands/npm-cache) for more on
+how the cache works.
+
+#### prefer-online
+
+Forces staleness checks for packages, making the cli look for updates
+immediately even if the package is already in the cache.
+
+#### prefer-offline
+
+Bypasses staleness checks for packages.  Missing data will still be
+requested from the server. To force full offline mode, use `offline`.
+
+#### offline
+
+Forces full offline mode. Any packages not locally cached will result in
+an error.
+
 ### See Also
 
 * [init-package-json module](http://npm.im/init-package-json)
 * [package.json](/configuring-npm/package-json)
 * [npm version](/commands/npm-version)
 * [npm scope](/using-npm/scope)
+* [npm exec](/commands/npm-exec)

docs/content/commands/npm-search.md

@@ -110,13 +110,13 @@ on how the cache works.
 
 #### prefer-online
 
-Forced staleness checks for cached searches, making the cli look for
+Forces staleness checks for cached searches, making the cli look for
 updates immediately even for fresh search results.
 
 #### prefer-offline
 
-Bypasses staleness checks for cached.  Missing data will still be
-requested from the server. To force full offline mode, use `offline`.
+Bypasses staleness checks for cached searches.  Missing data will still
+be requested from the server. To force full offline mode, use `offline`.
 
 #### offline