doc: Reorganize documentation site content

Take the existing ACRN technical documentation and reorganize its
presentation to be persona and use-case based, in preparation for adding
new scenario/use-case based architecture introduction and getting
started documents.

Introduce a more graphical home page and theme color tweaks.

Signed-off-by: David B. Kinder <david.b.kinder@intel.com>

doc/developer-guides/images/boot-flow.dot

@@ -1,6 +0,0 @@
-digraph G {
-   rankdir=LR;
-   bgcolor="transparent";
-   UEFI -> "acrn.efi" -> "OS\nBootloader" ->
-     "SOS\nKernel" -> "ACRN\nDevice Model" -> "Virtual\nBootloader";
-}

doc/developer-guides/images/circle-square.dot

@@ -1,9 +0,0 @@
-digraph {
-   bgcolor="transparent"; rankdir=LR;
-   { a [shape=circle height="1" style=filled color=AntiqueWhite
-        label="Circle\nLabel"]
-     b [shape=box height="1" width="1" style="rounded,filled"
-        color="#F080F0" label="Square\nLabel"]
-   }
-   a -> b
-}

doc/developer-guides/images/gaspump.dot

@@ -1,11 +0,0 @@
-digraph gaspump {
-        rankdir=LR;
-        node [shape = circle;];
-        edge [color = grey; fontsize=10];
-        S0 -> S1 [ label = "Lift Nozzle" ]
-        S1 -> S0 [ label = "Replace Nozzle" ]
-        S1 -> S2 [ label = "Authorize Pump" ]
-        S2 -> S0 [ label = "Replace Nozzle" ]
-        S2 -> S3 [ label = "Pull Trigger" ]
-        S3 -> S2 [ label = "Release Trigger" ]
-}

doc/developer-guides/images/node-shape-edges.dot

@@ -1,8 +0,0 @@
-digraph {
-   bgcolor=transparent; rankdir=LR;
-   node [shape="rectangle" style="filled" color="lightblue"]
-   edge [fontsize="12" fontcolor="grey"]
-
-   "acrnprobe" -> "telemetrics-client" [label="crashlog\npath"]
-   "telemetrics-client" -> "backend"   [label="log\ncontent"]
-}

doc/developer-guides/images/record.dot

@@ -1,4 +0,0 @@
-digraph {
-   a [shape=record label="left | {above|middle|below} | <f1>right"]
-   b [shape=record label="{row1\l|row2\r|{row3\nleft|<f2>row3\nright}|row4}"]
-}

doc/developer-guides/images/trusty-boot-flow.dot

@@ -1,10 +0,0 @@
-digraph G {
-   rankdir=LR;
-   rank=same;
-   bgcolor="transparent";
-   uosl1 [label="UOS_Loader"]
-   acrn_init [shape=box style="rounded,filled" label="ACRN"]
-   acrn_switch [shape=box style="rounded,filled" label="ACRN"]
-   uosl2 [label="UOS_Loader"]
-   uosl1 -> acrn_init -> "Trusty" -> acrn_switch -> uosl2;
-}