docs: Decouple refrences from /docs folder

Signed-off-by: Anton Komlev <anton.komlev@arm.com>
Change-Id: I1955201382074eb9e6dd80aadbc456eb09aecb22
diff --git a/docs/index.rst b/docs/index.rst
index 955c28b..26207d7 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -15,7 +15,7 @@
 
     <ul class="grid">
         <li class="grid-item">
-            <a href="docs/introduction/readme.html">
+            <a href="introduction/readme.html">
                 <img alt="" src="_static/images/tfm-introduction.png"/>
                 <h2>Introduction</h2>
             </a>
@@ -23,7 +23,7 @@
                architecture, features, and licensing.</p>
         </li>
         <li class="grid-item">
-            <a href="docs/getting_started/index.html">
+            <a href="getting_started/index.html">
                <img alt="" src="_static/images/tfm-documentation.png"/>
                <h2>Getting Started</h2>
             </a>
@@ -38,7 +38,7 @@
             <p>List of supported boards and platforms.</p>
         </li>
         <li class="grid-item">
-            <a href="docs/contributing/index.html">
+            <a href="contributing/index.html">
                 <img alt="" src="_static/images/tfm-contribution.png"/>
                 <h2>Contribution</h2>
             </a>
@@ -46,21 +46,21 @@
                to submit patches directly to the project.</p>
         </li>
         <li class="grid-item">
-            <a href="docs/integration_guide/index.html">
+            <a href="integration_guide/index.html">
                 <img alt="" src="_static/images/tfm-integration.png"/>
                 <h2>Integration</h2>
             </a>
             <p>Guidelines for integration with TF-M.</p>
         </li>
         <li class="grid-item">
-            <a href="docs/technical_references/index.html">
+            <a href="technical_references/index.html">
                 <img alt="" src="_static/images/tfm-reference.png"/>
                 <h2>References</h2>
             </a>
             <p>Design documents.</p>
         </li>
         <li class="grid-item">
-            <a href="docs/security/index.html">
+            <a href="security/index.html">
                 <img alt="" src="_static/images/tfm.png"/>
                 <h2>Security</h2>
             </a>
@@ -68,7 +68,7 @@
                is addressed within the TF-M project.</p>
         </li>
         <li class="grid-item">
-            <a href="docs/releases/index.html">
+            <a href="releases/index.html">
                 <img alt="" src="_static/images/tfm-release.png"/>
                 <h2>Releases</h2>
             </a>
@@ -84,14 +84,14 @@
     :hidden:
 
     Home<self>
-    docs/introduction/index
-    docs/getting_started/index
+    introduction/index
+    getting_started/index
     platform/ext/index
-    docs/contributing/index
-    docs/integration_guide/index
-    docs/technical_references/index
-    docs/security/index
-    docs/releases/index
+    contributing/index
+    integration_guide/index
+    technical_references/index
+    security/index
+    releases/index
 
 
 .. toctree::
@@ -102,7 +102,7 @@
     API Reference <https://ci.trustedfirmware.org/view/TF-M/job/tf-m-build-docs-nightly/lastSuccessfulBuild/artifact/trusted-firmware-m/build/docs/reference_manual/html/index.html>
     Security Center <https://developer.trustedfirmware.org/w/collaboration/security_center>
     Platform Security Architecture <https://developer.arm.com/architectures/security-architectures/platform-security-architecture>
-    docs/glossary
+    glossary
 
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