Add missing full stop to Linux-specific build instructions

docs/linux_build_instructions.md

 # Linux-specific build instructions
 
 [TOC]
 
 ## Get the code
 
 [Get the Code](https://www.chromium.org/developers/how-tos/get-the-code). The
 general instructions on the "Get the code" page cover basic Linux build setup
 and configuration.
 
@@ skipping 115 matching lines @@
 1.  Build in Release mode (debugging symbols require a lot of memory)
 1.  Build as shared libraries (note: this build is for developers only, and may
     have broken functionality)
 
 Most of these are described on the [Linux Faster Builds](linux_faster_builds.md)
 page.
 
 ## Advanced Features
 
 *   Want to use the (in development) GN build workflow? See
-    [GN Quick Start](../tools/gn/docs/quick_start.md)
+    [GN Quick Start](../tools/gn/docs/quick_start.md).
 *   Building frequently? See [LinuxFasterBuilds](linux_faster_builds.md).
 *   Cross-compiling for ARM? See [LinuxChromiumArm](linux_chromium_arm.md).
 *   Want to use Eclipse as your IDE? See
     [LinuxEclipseDev](linux_eclipse_dev.md).
 *   Built version as Default Browser? See
     [LinuxDevBuildAsDefaultBrowser](linux_dev_build_as_default_browser.md).
 
 ## Next Steps
 
 If you want to contribute to the effort toward a Chromium-based browser for
 Linux, please check out the [Linux Development page](linux_development.md) for
 more information.