Fix relative links to absolute ones instead

Author: Julien Debon

docs/contributing/contributing.md

@@ -113,7 +113,7 @@ $ cabal run haskell-language-server:func-test -- -p "hlint enables"
 
 ## Using HLS on HLS code
 
-[HLS project configuration guidelines](../configuration.md#configuring-your-project-build) also apply to the HLS project itself.
+[HLS project configuration guidelines](https://haskell-language-server.readthedocs.io/en/latest/configuration.html#configuring-your-project-build) also apply to the HLS project itself.
 
 Note: HLS implicitly detects HLS codebase as a Stack project (see [hie-bios implicit configuration documentation](https://github.com/haskell/hie-bios/blob/master/README.md#implicit-configuration)).
 If you want HLS to use Cabal, you need to create an `hie.yaml` file:
@@ -196,7 +196,7 @@ If you don't want to use [nix](https://nixos.org/guides/install-nix.html), you c
 
 ## Introduction tutorial
 
-See the [tutorial](./plugin-tutorial.md) on writing a plugin in HLS.
+See the [tutorial](https://haskell-language-server.readthedocs.io/en/latest/contributing/plugin-tutorial.html) on writing a plugin in HLS.
 
 ## Adding support for a new editor
 

docs/features.md

@@ -3,7 +3,7 @@
 You can watch demos for some of these features [below](#demos).
 
 - Warning and error diagnostics from GHC
-- Type information and documentation on hover, [including your own comments](./configuration.md#how-to-show-local-documentation-on-hover).
+- Type information and documentation on hover, [including your own comments](https://haskell-language-server.readthedocs.io/en/latest/configuration.html#how-to-show-local-documentation-on-hover).
 - Jump to definition: [for now only for local code definitions](https://github.com/haskell/haskell-language-server/issues/708)
 - Document symbols
 - Highlight references in document

install/README.md

@@ -1,7 +1,7 @@
 # hls-install
 
 This directory contains the `hls-install` project, an Haskell Language Server installer.
-It is used when [installing from sources](../docs/installation.md#building).
+It is used when [installing from sources](https://haskell-language-server.readthedocs.io/en/latest/installation.html#building).
 
 Unlike other subdirectories (e.g. `hls-graph` or `ghcide`), this is not another package of the HLS project, but another project entirely (with another `stack.yaml`, another `cabal.project`, etc.). It just so happens to be in a subdirectory of HLS project for convenience, as this is tightly related to HLS.