added readme info

README.md

@@ -1,5 +1,14 @@
 # faircoin-calculator
 
-Very simple Faircoin calculator.
+Simple Faircoin calculator to show the historical value of FairCoin at any given date.
+
+The price dataset is from http://api.fairplayground.info/rawdata/faircoin_prices.csv
+
+You can use it on the web at http://mayel.space/faircoin-calculator/ or install the browser extension which displays the value of FairCoin at the time of each transaction when <a href="https://chain.fair.to/">browsing the blockchain.</a>
+
+Extension available for <a href="https://addons.mozilla.org/en-US/firefox/addon/faircoin-calculator/">Firefox</a> and <a href="https://chrome.google.com/webstore/detail/faircoin-calculator/alnbjhldpppajfdoknbdpienjbiogmlp">Chrome</a>.
+
+If you're happy with the FairCoin Calculator, you can donate at <a href="faircoin:fMGcrP9nAFic4356F4oHDDWVq8YvtJSXZL">fMGcrP9nAFic4356F4oHDDWVq8YvtJSXZL</a>
+
+
 
-The price dataset is getted from http://api.fairplayground.info/rawdata/faircoin_prices.csv

extension/extension.js

@@ -11,6 +11,9 @@ $(function() {
         //   $(".inner-cont").append("priceData: ");
         //   $(".inner-cont").append(priceData);
 
+          var heads = "<p style='text-align:center;'>If you're happy with the FairCoin Calculator, you can donate at <a href='faircoin:fMGcrP9nAFic4356F4oHDDWVq8YvtJSXZL'>fMGcrP9nAFic4356F4oHDDWVq8YvtJSXZL</a>";
+		$("body").append(heads);
+
         if (priceData) {
 
         	var heads = '<th>Official Rate</th><th>Official Value</th><th>Market Value</th>';

index.html

@@ -63,10 +63,19 @@
             </div>
           </div>
         </div>
+
+
+  <p> You can also use the browser extension which displays the historical value of FairCoin at the time of each transaction when <a href="https://chain.fair.to/">browsing the blockchain.</a> Available for <a href="https://addons.mozilla.org/en-US/firefox/addon/faircoin-calculator/">Firefox</a> and <a href="https://chrome.google.com/webstore/detail/faircoin-calculator/alnbjhldpppajfdoknbdpienjbiogmlp">Chrome</a>.
+  <p>If you're happy with the FairCoin Calculator, you can donate at <a href="faircoin:fMGcrP9nAFic4356F4oHDDWVq8YvtJSXZL">fMGcrP9nAFic4356F4oHDDWVq8YvtJSXZL</a>
+
       </div>
+
     </div>
+
   </div>
 
+
+
   <!-- bootstrap -->
   <!-- jQuery first, then Popper.js, then Bootstrap JS -->
   <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>