ots: soften the operator-credit paragraph

'eat the Bitcoin transaction fees out of pocket' implied burden;
'sponsor' is more positive and accurate -- they choose to run this,
they're not stuck with it. Also dropped the 'elegant trick' framing
and trimmed 'user submissions' to 'submissions'.

Author: hans-crypto

frontend/src/app/components/_ordpool/ots-calendars/ots-calendars.component.html

@@ -17,12 +17,10 @@ <h1>OpenTimestamps: Anchor any file to Bitcoin</h1>
   </p>
 
   <p>
-    The whole process is <strong>free</strong>. Calendar operators eat the
-    Bitcoin transaction fees out of pocket and amortise them across thousands
-    of users by Merkle-batching. We just route your hash to them; we don't run
-    the calendars and we don't charge anything. Big thanks to the operators
-    keeping this running as a public good (see the <a href="#calendars">list
-    below</a>).
+    The whole process is <strong>free</strong>. Calendar operators sponsor the
+    Bitcoin transaction fees and Merkle-batch thousands of submissions per
+    anchor. Huge thanks to the operators (see the <a href="#calendars">list
+    below</a>) who keep this open public good alive.
   </p>
 
   <p class="text-muted ots-sidenote">