doc/api: improve readability of the API docs

Still not great and probably makes any professional designer's eyes bleed, but
at least it's more readable now.

Changes:
- spacing after param name so they don't cuddle up with the description
- color changes and background image removals to drop the doxygen default look
- font size changes to not make things overrun
- font family change to make the function prototypes readable

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

doc/api/style/libinputdoxygen.css

@@ -1,14 +1,23 @@
+@import url("https://fonts.googleapis.com/css?family=Roboto+Mono");
+
 dd {
     margin-left: 30px;
 }
 
 .title {
-	font-size: 400%;
-	font-weight: 200;
+	font-size: 200%;
+	font-weight: bold;
+}
+
+.title .ingroups {
+	font-size: 200%;
 }
 
 h1 {
 	font-size: 300%;
+	background-image: none;
+	background-color: #D6E5FF;
+	padding-left: 10px;
 }
 
 h2 {
@@ -45,3 +54,43 @@ h2 {
 #main-menu li ul {
 	display: none;
 }
+
+.paramname {
+	padding-right: 10px;
+}
+
+.memtitle {
+	background-image: none;
+	background-color: #F0F0F0;
+}
+
+.memproto {
+	background-color: #F0F0F0;
+}
+
+.headertitle {
+	background-image: none;
+	background-color: #F0F0F0;
+}
+
+td.fieldname {
+	font-family: 'Roboto Mono', monospace;
+}
+
+.fieldtable th {
+	background-image: none;
+	background-color: #F0F0F0;
+}
+
+body {
+	letter-spacing: 0px;
+}
+
+.mdescLeft, .mdescRight, .memItemLeft, .memItemRight, .memTemplItemLeft, .memTemplItemRight, .memTemplParams {
+	background-color: #F0F0F0;
+}
+
+a {
+	color: #2873b0;
+
+}

src/libinput.h

@@ -2400,7 +2400,7 @@ libinput_event_tablet_tool_get_time_usec(struct libinput_event_tablet_tool *even
  * mapped to an eraser-like virtual tool.
  *
  * If supported by the hardware, a more specific tool id is always
- * available, see * libinput_tablet_tool_get_tool_id().
+ * available, see libinput_tablet_tool_get_tool_id().
  *
  * @param tool The libinput tool
  * @return The tool type for this tool object