Jeopardy has a team of writers and researchers for the questions and categories. Feel free to contact them because they will decide if your category suggestions have merit regardless of what was done previously.
Jeopardy! questions cover an encyclopedia worth of categories taken from Science, History, Pop Culture, Literature, Geography, etc... Examples of traditional Jeopardy! categories are: The Oscars, Literary Characters, Word Origins, and U.S. Presidents. Some of Jeopardy's categories with a twist are: Before & After, Rhyme Time, Stupid Answers, and Name's the Same.
Jeopardy is the show with categories
Common categories on Jeopardy focus on general topics such as history, geography, literature, food & drink and sports & entertainment. Other categories might be more specific, focusing on history of a certain country or an entire category devoted to one famous person. Then there are the novelty categories such as "Rhyme Time", "Names the Same" and "Stupid Answers."
MOSES
6 categories with 5 questions in both the Jeopardy and Double Jeopardy round total 60 Squares
All of the Jeopardy game is available in a record on the related link
The Jeopardy! production staff has six researchers and 10 writers whose jobs are to create and assemble categories and questions for the series.
Jeopardy has many more than 5 main categories of its Questions/clues and the show itself could be said to have different parts or acts like an introduction , single , double , and final Jeopardy. There would also be when the winner is determined if that was the five you were asking about. They is also a commercial break as part of the single Jeopardy round
Related link has the season 27 Categories question and answers for the Jeopardy by the air date of the orginal episode
You can find the answer under the related question
WikiAnswers' higher Supervisors are the ones who take in the suggestions and add them, regular members do not add categories or sub-categories.
The categories in the Double Jeopardy! Round on Tuesday, October 20, 2009 were World Cities, The Comeback Kids, Poetry Time, 5 Other Senses, An End For "U" and "Me", and Famous Trials.