Add 3NF violations explained step (GH-202)

src/rdbms/presentations/normalization/_index.hbs

@@ -101,9 +101,12 @@
     <div class="step" id="req-3nf"
          data-x="1800"
          data-y="2000">{{>req-3nf}}</div>
+    <div class="step" id="problem-3nf"
+         data-rel-position="relative"
+         data-rel-y="2000">{{>problem-3nf}}</div>
     <div class="step" id="example-3nf"
          data-rel-position="relative"
-         data-rel-y="1000">{{>example-3nf}}</div>
+         data-rel-y="-1000">{{>example-3nf}}</div>
     {{! overview step }}
     <div class="step overview" id="overview" data-x="0" data-y="0" data-scale="5"></div>
 

src/rdbms/presentations/normalization/problem-3nf.hbs

@@ -0,0 +1,4 @@
+{{!
+  transitive dependencies should be eliminated
+}}
+<div>{{>tbl-3nf-tdp}}</div>

src/rdbms/presentations/normalization/tbl-3nf-tdp.hbs

@@ -0,0 +1,28 @@
+{{! transitive dependencies }}
+<table class="db-table" id="tbl-3nf-tdp" aria-label="second normal form table">
+  <caption>Player Level</caption>
+  <thead>
+  <tr id="tbl-3nf-tdp__level">
+    <th scope="col" class="primary-key">name</th>
+    <th scope="col">level</th>
+    <th scope="col">rating</th>
+  </tr>
+  </thead>
+  <tbody>
+  <tr id="tbl-3nf-tdp__prombery87">
+    <td class="primary-key">prombery87</td>
+    <td class="text-center">7</td>
+    <td class="text-center">Advanced</td>
+  </tr>
+  <tr id="tbl-3nf-tdp__wheed1997">
+    <td class="primary-key">wheed1997</td>
+    <td class="text-center">6</td>
+    <td class="text-center">Intermediate</td>
+  </tr>
+  <tr id="tbl-3nf-tdp__acen1997">
+    <td class="primary-key">acen1997</td>
+    <td class="text-center">1</td>
+    <td class="text-center">Beginner</td>
+  </tr>
+  </tbody>
+</table>