Fix images on /providers/ and site favicons (#1568)

_includes/head.html

@@ -17,7 +17,7 @@
   {% endif %}
   <meta property="og:type" content="website" />
   <meta property="og:url" content="{{ page.permalink | prepend: site.url }}" />
-  <meta property="og:image" content="{{ site.production_url }}/assets/img/layout/ogimage.jpg" />
+  <meta property="og:image" content="{{ site.production_url }}/assets/img/svg/layout/brand/square-transparent.svg" />
   <meta property="og:description" content="{% if page.description %}{{ page.description }}{% else %}{{ site.description }}{% endif %}"/>
   <meta property="og:locale" content="en_GB" />
   <meta property="og:site_name" content="{{ site.name }}" />
@@ -35,7 +35,7 @@
       "privacytoolsIO"
     ],
     "url": "{{ site.production_url }}",
-    "logo": "{{ site.production_url }}/assets/img/png/layout/shield.png",
+    "logo": "{{ site.production_url }}/assets/img/svg/layout/brand/square-transparent.svg",
     "sameAs": [
       "https://blog.privacytools.io",
       "https://twitter.com/privacytoolsIO",

_includes/sections/key-disclosure-law.html

@@ -67,7 +67,7 @@
 
 <h3 id="usa" class="anchor">Why is it not recommended to choose a US-based service?</h3>
 
-<img src="/assets/img/layout/USA.png" width="200" height="200" class="img-fluid float-right ml-3" alt="USA">
+<img src="/assets/img/svg/layout/great_seal_of_the_united_states_obverse.svg" width="200" height="200" class="img-fluid float-right ml-3" alt="USA">
 
 <p>Services based in the United States are not recommended because of the country's surveillance programs and use of <a href="https://www.eff.org/issues/national-security-letters/faq">National Security Letters</a> (NSLs) with accompanying gag orders, which forbid the recipient from talking about the request. This combination allows the government to <a href="https://www.schneier.com/blog/archives/2013/08/more_on_the_nsa.html">secretly force</a> companies to grant complete access to customer data and transform the service into a tool of mass surveillance.</p>
 

_includes/sections/warrant-canary.html

@@ -1,6 +1,6 @@
 <h1 id="wc" class="anchor"><a href="#wc"><i class="fas fa-link anchor-icon"></i></a> What is a warrant canary?</h1>
 
-<img src="/assets/img/layout/warrant-canary.jpg" width="450" height="236" class="img-fluid float-right ml-3" alt="Warrant Canary Example">
+<img src="/assets/img/svg/layout/warrant_canary_example.svg" width="450px" class="img-fluid float-right ml-3" alt="Warrant Canary Example">
 
 <p>A warrant canary is a posted document stating that an organization has not received any secret subpoenas during a specific period of time. If this document fails to be updated during the specified time then the user is to assume that the service has received such a subpoena and should stop using the service.</p>