Reduce verbosity of error messages, with addition of 500 and 429 pages

- Reduce verbosity of error messages in existing error pages with a
  short description of the error which occurred, followed by a bullet
  point list of probable causes.
- Addition of HTTP Error 500 and 429 pages.
- Add .gitignore file

.gitignore

@@ -0,0 +1,3 @@
+/output
+/suo
+/*.sh

input/error/403.html

@@ -1,10 +1,17 @@
-[//]: # "Title: Access unauthorised"
+[//]: # "Title: Access Unauthorised"
 [//]: # "Summary: Access to this resource has been prohibited."
 
 <div class="err">
     <h1>Access Unauthorised</h1>
-    <p>Access to this resource has been prohibited, because either 
-    you have insufficient permissions to access this resource; or 
-    the ip address you're connecting from has been prohibited 
-    access to this server.</p>
+    <p>Access to this resource has been prohibited.</p>
+
+    <p>There could be a few reasons for this:</p>
+
+    <ul>
+        <li>Insufficient permission to access this resource;</li>
+        <li>Connecting from a blocked network, or;</li>
+        <li>A network associated with malicious traffic.</li>
+    </ul>
+
+    <p>If you believe this to be in error, e-mail <a href="mailto:3EjmZHiLR@mozmail.com" class="ml" a="ten.muiroza" b="nimda"></a>.</p>
 </div>

input/error/404.html

@@ -4,4 +4,11 @@
 <div class="err">
     <h1>Not Found</h1>
     <p>The resource requested not found on this server.</p>
+
+    <p>There could be a few reasons for this:</p>
+
+    <ul>
+        <li>The resource requested is no longer available, or;</li>
+        <li>There might be an error in the address provided.</li>
+    </ul>
 </div>

input/error/429.html

@@ -0,0 +1,17 @@
+[//]: # "Title: Too Many Reqests"
+[//]: # "Summary: Access to this resource has been throttled."
+
+<div class="err">
+    <h1>Too Many Requests</h1>
+    <p>Access to this resource has been throttled.</p>
+
+    <p>There could be a few reasons for this:</p>
+
+    <ul>
+        <li>The rate limit for this resource has been exhausted, or;</li>
+        <li>An excessive amount of traffic to this resource is 
+            originating from malicious traffic on your network.</li>
+    </ul>
+
+    <p>Please try again later.</p>
+</div>

input/error/500.html

@@ -0,0 +1,16 @@
+[//]: # "Title: Internal Server Error"
+[//]: # "Summary: An internal server error has occurred."
+
+<div class="err">
+    <h1>Internal Server Error</h1>
+    <p>An internal server error has occurred.</p>
+
+    <p>There could be a few reasons for this:</p>
+
+    <ul>
+        <li>An internal misconfiguration of this resource, or;</li>
+        <li>Maintenance of this resource is occurring.</li>
+    </ul>
+
+    <p>Please try again later, or <a href="https://status.sapphirus.net">check here</a> for further information.</p>
+</div>

input/error/502.html

@@ -1,8 +1,17 @@
 [//]: # "Title: Bad Gateway"
 [//]: # "Summary: The upstream resource is unavailable."
 
-<div class="err">             
+<div class="err">
     <h1>Bad Gateway</h1>
-    <p>The upstream resource is unavailable.<br>
-    Please try again later, or check <a href="https://status.sapphirus.net">here</a> for further information.</p>
+    <p>The upstream resource is unavailable.</p>
+
+    <p>There could be a few reasons for this:</p>
+
+    <ul>
+        <li>Maintenance of this resource is occurring;</li> 
+        <li>The upstream resource is unresponsive, or;</li>
+        <li>The upstream service is simply not available.</li>
+    </ul>
+
+    <p>Please try again later, or <a href="https://status.sapphirus.net">check here</a> for further information.</p>
 </div>

input/error/504.html

@@ -1,8 +1,17 @@
 [//]: # "Title: Gateway Timeout"
 [//]: # "Summary: The upstream resource is unavailable."
 
-<div class="err">             
+<div class="err">
     <h1>Gateway Timeout</h1>
-    <p>The upstream resource is unavailable.<br>
-    Please try again later, or check <a href="https://status.sapphirus.net">here</a> for further information.</p>
+    <p>The upstream resource is unavailable.</p>
+
+    <p>There could be a few reasons for this:</p>
+
+    <ul>
+        <li>Maintenance of this resource is occurring;</li> 
+        <li>The upstream resource is unresponsive, or;</li>
+        <li>The upstream service is simply not available.</li>
+    </ul>
+
+    <p>Please try again later, or <a href="https://status.sapphirus.net">check here</a> for further information.</p>
 </div>