minor #5636 Fixed typo in web-assets.rst (nielsvermaut)

This PR was submitted for the 2.8 branch but it was merged into the 2.3 branch instead (closes #5636).

Discussion
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Fixed typo in web-assets.rst

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all
| Fixed tickets |

Commits
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62fc0dc Update web-assets.rst

Author: xabbuh

best_practices/web-assets.rst

@@ -30,7 +30,7 @@ much more concise:
 
     Keep in mind that ``web/`` is a public directory and that anything stored
     here will be publicly accessible, including all the original asset files
-    (e.g. Sass, LESS and CoffeScript files).
+    (e.g. Sass, LESS and CoffeeScript files).
 
 Using Assetic
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