markdownlint: fix all warnings

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I1e1dde26ac66e8296253c24c39a2ccb3964b1da0
diff --git a/README.md b/README.md
index 330514d..95ddb48 100644
--- a/README.md
+++ b/README.md
@@ -21,7 +21,7 @@
 
 ### The Buffer Mode
 
-```
+```text
 +-------------+                                       +----------------+
 |    Host     | State  +---------------------+ Event  |   Host Logger  |
 |             |------->|        D-Bus        |------->|                |
@@ -43,7 +43,7 @@
 
 ### The Stream Mode
 
-```
+```text
 +-----------+                               +-------------+      +------------+
 |           |                               |             |      |            |
 |   Host    |                               | Host Logger |      |  rsyslog   |
@@ -156,14 +156,14 @@
 
 File `phosphor-hostlogger_%.bbappend`:
 
-```
-FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
-SRC_URI_append = " file://ttyVUART0.conf"
+```bitbake
+FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}:"
+SRC_URI:append = " file://ttyVUART0.conf"
 ```
 
 File `phosphor-hostlogger/ttyVUART0.conf`:
 
-```
+```sh
 MAX_FILES=0
 ```
 
@@ -174,14 +174,14 @@
 
 File `phosphor-hostlogger_%.bbappend`:
 
-```
-FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
-SRC_URI_append = " file://ttyS2.conf"
+```bitbake
+FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}:"
+SRC_URI:append = " file://ttyS2.conf"
 ```
 
 File `phosphor-hostlogger/ttyS2.conf`:
 
-```
+```sh
 HOST_STATE=/xyz/openbmc_project/state/os
 ```