docs: update demo to 0.7.0 (#941)

* docs: update demo to 0.7.0

* update again

Author: ClementTsang

README.md

@@ -12,8 +12,8 @@
 
 </div>
 
-<img src="assets/demo.gif" alt="Quick demo recording showing off bottom's searching, expanding, and process killing."/>
 <div align="center">
+  <img src="assets/demo.gif" alt="Quick demo recording showing off bottom's searching, expanding, and process killing."/>
   <p>
     Demo GIF using the <a href="https://github.com/morhetz/gruvbox">Gruvbox</a> theme (<code>--color gruvbox</code>), along with <a href="https://www.ibm.com/plex/">IBM Plex Mono</a> and <a href="https://sw.kovidgoyal.net/kitty/">Kitty</a>
   </p>

assets/demo.gif

@@ -222,6 +222,7 @@ impl ProcWidgetData {
 impl DataToCell<ProcColumn> for ProcWidgetData {
     fn to_cell<'a>(&'a self, column: &ProcColumn, calculated_width: u16) -> Option<Text<'a>> {
         // TODO: Optimize the string allocations here...
+        // TODO: Also maybe just pull in the to_string call but add a variable for the differences.
         Some(truncate_to_text(
             &match column {
                 ProcColumn::CpuPercent => {