Add HTC-specific fastboot instructions and update
relevant device markdowns

Newer HTC devices require recovery to be flashed from Download mode,
not bootloader. Update "adb reboot bootloader" command to
"adb reboot download" so that the instructions are correct.

Change-Id: I6a833464835c2cb8ab976fcbf5ee8630623f1382
diff --git a/_devices/htc10.markdown b/_devices/htc10.markdown
index cf43da7..fa7ed91 100644
--- a/_devices/htc10.markdown
+++ b/_devices/htc10.markdown
@@ -19,6 +19,6 @@
 
 {% include twrpinstall.html %}
 
-{% include fastbootinstall.html %}
+{% include fastbootinstallhtc.html %}
 
 {% include ddinstall.html %}
diff --git a/_devices/htcdesire626s.markdown b/_devices/htcdesire626s.markdown
index 199c8fb..e4aaccc 100644
--- a/_devices/htcdesire626s.markdown
+++ b/_devices/htcdesire626s.markdown
@@ -19,6 +19,6 @@
 
 {% include twrpinstall.html %}
 
-{% include fastbootinstall.html %}
+{% include fastbootinstallhtc.html %}
 
 {% include ddinstall.html %}
diff --git a/_devices/htconea9.markdown b/_devices/htconea9.markdown
index 5d10f1c..5f91b34 100644
--- a/_devices/htconea9.markdown
+++ b/_devices/htconea9.markdown
@@ -19,6 +19,6 @@
 
 {% include twrpinstall.html %}
 
-{% include fastbootinstall.html %}
+{% include fastbootinstallhtc.html %}
 
 {% include ddinstall.html %}
diff --git a/_devices/htconem9.markdown b/_devices/htconem9.markdown
index b68f843..0add0e0 100644
--- a/_devices/htconem9.markdown
+++ b/_devices/htconem9.markdown
@@ -22,6 +22,6 @@
 
 {% include twrpinstall.html %}
 
-{% include fastbootinstall.html %}
+{% include fastbootinstallhtc.html %}
 
 {% include ddinstall.html %}