Change all doc links to use relative names

Github pages assumes that links to files using relative
names point to the same location so this should work both
when accessing through the github browser and mcuboot.com

Signed-off-by: Fabio Utzig <utzig@apache.org>
diff --git a/docs/design.md b/docs/design.md
index 24f988a..3b6e335 100644
--- a/docs/design.md
+++ b/docs/design.md
@@ -682,5 +682,4 @@
 TLV.
 
 For information on embedding public keys in the boot loader, as well as
-producing signed images, see: [signed_images]({% link signed_images.md
-%}).
+producing signed images, see: [signed_images](signed_images.md).
diff --git a/docs/index.md b/docs/index.md
index 9be0edf..8a40238 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -16,23 +16,22 @@
 ## Contents
 
 - General: this document
-- [Release notes]({% link release-notes.md %})
-- [design]({% link design.md %}): for the design
-- [imgtool]({% link imgtool.md %}): The image signing and key management
+- [Release notes](release-notes.md)
+- [design](design.md): for the design
+- [imgtool](imgtool.md): The image signing and key management
 - Usage instructions:
-  - [Zephyr]({% link readme-zephyr.md %})
-  - [Mynewt]({% link readme-mynewt.md %})
-  - [RIOT]({% link readme-riot.md %})
-- [Patch submission]({% link SubmittingPatches.md %}) for information
+  - [Zephyr](readme-zephyr.md)
+  - [Mynewt](readme-mynewt.md)
+  - [RIOT](readme-riot.md)
+- [Patch submission](SubmittingPatches.md) for information
   on how to contribute to mcuboot.
 - Testing
-  - The [Zephyr]({% link testplan-zephyr.md %}) test plan.
-  - The [mynewt]({% link testplan-mynewt.md %}) test plan.
-- Our [release process]({% link release.md %}).
+  - The [Zephyr](testplan-zephyr.md) test plan.
+  - The [mynewt](testplan-mynewt.md) test plan.
+- Our [release process](release.md).
 
-There is also a document about [signed images]({% link
-signed_images.md %}) that is out of date.  You should use `imgtool.py`
-instead of these documents.
+There is also a document about [signed images](signed_images.md) that is out
+of date.  You should use `imgtool.py` instead of these documents.
 
 ## Roadmap
 
diff --git a/docs/readme-zephyr.md b/docs/readme-zephyr.md
index 3737f3f..c4439fa 100644
--- a/docs/readme-zephyr.md
+++ b/docs/readme-zephyr.md
@@ -5,9 +5,9 @@
 There are some pretty significant differences in how apps are built
 for Zephyr, and these are documented here.
 
-Please see the [design document]({% link design.md %}) for documentation on the
-design and operation of the bootloader itself.  This functionality
-should be the same on all supported RTOSs.
+Please see the [design document](design.md) for documentation on the design
+and operation of the bootloader itself. This functionality should be the same
+on all supported RTOSs.
 
 The first step required for Zephyr is making sure your board has flash
 partitions defined in its device tree. These partitions are:
diff --git a/docs/release-notes.md b/docs/release-notes.md
index 3664139..69b6b1a 100644
--- a/docs/release-notes.md
+++ b/docs/release-notes.md
@@ -63,8 +63,8 @@
   - Nordic nRF51 and nRF52832 dev kits
   - Hexiwear K64
 - Clearer sample applications have been added under `samples`.
-- Test plans for [zephyr](%{ link testplan-zephyr.md %}), and
-  [mynewt]({% link testplan-mynewt.md %}).
+- Test plans for [zephyr](testplan-zephyr.md), and
+  [mynewt](testplan-mynewt.md).
 - The simulator is now able to test RSA signatures.
 - There is an unimplemented `load_addr` header for future support for
   RAM loading in the bootloader.