fix some dead links in the welcome page (#587)

ext/settings.html

@@ -2479,7 +2479,7 @@ <h1>Yomitan Settings</h1>
 
         <div class="warning-text margin-above no-dictionaries-installed-warning" hidden>
             No dictionaries have been installed yet.
-            Visit the <a href="https://github.com/themoeway/yomitan#dictionaries" target="_blank" rel="noopener noreferrer">Yomitan homepage</a>
+            Visit the <a href="https://github.com/themoeway/yomitan/blob/master/docs/dictionaries.md#dictionaries" target="_blank" rel="noopener noreferrer">Yomitan homepage</a>
             for a list of free dictionaries or click the <em>Import</em> button below to select a dictionary file to import.
         </div>
         <div id="dictionary-error" class="danger-text margin-above" hidden></div>

ext/welcome.html

@@ -30,7 +30,7 @@ <h1>Welcome to Yomitan!</h1>
       <div class="settings-item">
         <div class="settings-item-inner settings-item-inner-wrappable"><div class="settings-item-left"><div class="settings-item-label">
               <p>
-                There are custom Anki templates in your settings. Note that <a href="https://github.com/themoeway/yomitan#custom-templates" target="_blank" rel="noopener noreferrer">some syntax has changed from previous versions of Yomitan.</a>
+                There are custom Anki templates in your settings. Note that <a href="https://github.com/themoeway/yomitan/blob/master/docs/yomichan-migration.md#custom-templates" target="_blank" rel="noopener noreferrer">some syntax has changed from previous versions of Yomitan.</a>
                 Please ensure that your custom templates are using the updated syntax.
               </p>
           </div></div></div>
@@ -62,7 +62,7 @@ <h2>Here are some basics to get started</h2>
         <div class="settings-item">
             <div class="settings-item-inner"><div class="settings-item-left"><div class="settings-item-label">
                 Yomitan requires one or more dictionaries to be installed in order to look up terms, kanji, and other information.
-                Several downloadable dictionaries can be found on the <a href="https://github.com/themoeway/yomitan#dictionaries" target="_blank" rel="noopener noreferrer">Yomitan homepage</a>.
+                Several downloadable dictionaries can be found on the <a href="https://github.com/themoeway/yomitan/blob/master/docs/dictionaries.md#dictionaries" target="_blank" rel="noopener noreferrer">Yomitan homepage</a>.
                 Dictionaries can be configured using the button below,
                 or later from the <a href="/settings.html" rel="noopener">Settings</a> page.
             </div></div></div>
@@ -84,11 +84,11 @@ <h2>Here are some basics to get started</h2>
                 <br><br>
 
                 If you are migrating from Yomichan, you may be interested in importing your data into Yomitan.
-                Please follow instructions from <a href="https://github.com/themoeway/yomitan#migrating-from-yomichan" target="_blank" rel="noopener noreferrer">Yomitan's README</a> for that.
+                Please follow instructions from <a href="https://github.com/themoeway/yomitan/blob/master/docs/yomichan-migration.md#migrating-from-yomichan" target="_blank" rel="noopener noreferrer">Yomitan's README</a> for that.
 
                 <br><br>
 
-                If you are using or planning to use custom templates for Anki note creation, note that <a href="https://github.com/themoeway/yomitan#custom-templates" target="_blank" rel="noopener noreferrer">some syntax has changed from Yomichan and Yomibaba.</a>
+                If you are using or planning to use custom templates for Anki note creation, note that <a href="https://github.com/themoeway/yomitan/blob/master/docs/yomichan-migration.md#custom-templates" target="_blank" rel="noopener noreferrer">some syntax has changed from Yomichan and Yomibaba.</a>
                 Please ensure that your custom templates are using the updated syntax.
             </div></div></div>
         </div>
@@ -284,7 +284,7 @@ <h2>Basic customization</h2>
 
         <div class="warning-text margin-above no-dictionaries-installed-warning" hidden>
             No dictionaries have been installed yet.
-            Visit the <a href="https://github.com/themoeway/yomitan#dictionaries" target="_blank" rel="noopener noreferrer">Yomitan homepage</a>
+            Visit the <a href="https://github.com/themoeway/yomitan/blob/master/docs/dictionaries.md#dictionaries" target="_blank" rel="noopener noreferrer">Yomitan homepage</a>
             for a list of free dictionaries or click the <em>Import</em> button below to select a dictionary file to import.
         </div>
         <div id="dictionary-error" class="danger-text margin-above" hidden></div>