add FAQ: Why is a given word not in your list

Author: lcn2

README.md

@@ -47,6 +47,14 @@ If you find a word in our list that you think should be removed, then please ope
 
 If you do wish remove words from our list, then we ask that you consider in your same [pull request](https://github.com/lcn2/polite.words/pulls) to add some new words to keep the polite English language word list long.   See below for "Q: How do I add polite English language words to your list?" as well as for "Q: What is allowed in the word list?".
 
+## Q: Why is a given word not in your list?
+
+A word may be missing from the [polite.english.words.txt](https://github.com/lcn2/polite.english.words/blob/master/polite.english.words.txt) file simply because nobody has added it so far.  In some cases a otherwise perfectly polite word may have been removed because in combination with other words, the word in question would be considered impolite by most people.  It is also possible that the word may have been removed by mistake.
+
+If you find a polite word that is missing from the [polite.english.words.txt](https://github.com/lcn2/polite.english.words/blob/master/polite.english.words.txt) file, then **PLEASE** open a [pull request](https://github.com/lcn2/polite.words/pulls) to recommend that the polite word be added.
+
+See below for the "Q: How do I add polite English language words to your list?".
+
 ## Q: How do I add polite English language words to your list?
 
 **A**: We are happy to accept reasonable suggestions adding English language words to our list.