corrected some pages

Several small corrections were done to several proofs and definitions.

Author: JoramSoch

D/samp.md

@@ -31,6 +31,4 @@ username: "JoramSoch"
 
 $$ \label{eq:samp}
 x = \left\lbrace x_1, \ldots, x_n \right\rbrace \; .
-$$
-
-The number of elements in a sample is called "[sample size](/D/samp-size)".
+$$

_layouts/definition.html

@@ -54,7 +54,7 @@ <h1 class="post-title">Definition: {{ page.title }}</h1>
 
   <!-- "edit this definition" -->
   <div style="text-align:right">
-    <small><a href="https://github.com/StatProofBook/StatProofBook.github.io/blob/master/D/{{ page.shortcut }}.md">view/edit this definition</a></small>
+    <small><a href="https://github.com/StatProofBook/StatProofBook.github.io/blob/master/D/{{ page.shortcut }}.md">view/edit this definition</a></small><br>
 	<small><a href="/citations/">cite this definition</a></small>
   </div>