Add syntax highlight + link on Markdowns (#497)

* Add code syntax highlight

Add syntax highlight to C and Python codes

* Add hyperlink on XDMA README

Author: iomartin

sdk/apps/virtual-ethernet/doc/Virtual_Ethernet_Application_Guide.md

@@ -328,7 +328,7 @@ lspci -D | grep "1d0f:ec20"
 
 Within `<install_dir>/dpdk/drivers/net/spp` there is a file called `spp_ethdev.c`.  Your Vendor and Device ID should be added to the following table in `spp_ethdev.c` and then DPDK should be recompiled.
 
-```
+```C
 static const struct rte_pci_id pci_id_spp_map[] = {
         { RTE_PCI_DEVICE(PCI_VENDOR_ID_AMAZON, PCI_DEVICE_ID_SDE_LOOPBACK_CL) },
         { RTE_PCI_DEVICE(<Your Vendor ID>, <Your Device ID>) },
@@ -345,7 +345,7 @@ make
 
 Within `<install dir>/dpdk/usertools` there is a file called `dpdk-devbind.py`.  Your Vendor and Device ID should be added to the following table in `dpdk-devbind.py`.
 
-```
+```python
 aws_fpga_sde = {'Class': '05', 'Vendor': '1d0f', 'Device': 'f002',
               'SVendor': None, 'SDevice': None}
 <your tag> = {'Class': '05', 'Vendor': '<Your Vendor ID>', 'Device': '<Your Device ID>',

sdk/linux_kernel_drivers/xdma/README.md

@@ -42,7 +42,7 @@ Before diving into the detail specification of the XDMA, here’s a short, intui
 The Program below uses standard Linux system call `open()` to create a file descriptor (fd), mapping to a pair of XDMA channels (one for `read()` and one for `write()`).  The XDMA hardware engine is named the `XDMA Core`.  The XDMA write channel is called H2C (Host to Core).  The XDMA read channel is called C2H (Core to Host). The Core refers to the FPGA and the Host refers to the instance CPU.
 
 
-```
+```C
 #include <stdlib.h>
 #include <stdio.h>
 #include <fcntl.h>
@@ -199,7 +199,7 @@ Only the POLLIN mask is supported and is used to notify that an event has occurr
 
 Refer to [User-defined interrupts events README](./user_defined_interrupts_README.md) for more details.
 
-The application MUST issue a `pread` of the ready file descriptor to return and clear the `events_irq` variable within the XDMA driver in order to be notified of future user interrupts.  An example of using `poll` and `pread` for user defined interrupts is provided within the test_dram_dma.c `interrupt_example()`.
+The application MUST issue a `pread` of the ready file descriptor to return and clear the `events_irq` variable within the XDMA driver in order to be notified of future user interrupts.  An example of using `poll` and `pread` for user defined interrupts is provided within the [test_dram_dma.c](../../../hdk/cl/examples/cl_dram_dma/software/runtime/test_dram_dma.c) `interrupt_example()`.
 
 <a name="concurrency"></a>
 ## Concurrency and Multi-Threading

sdk/linux_kernel_drivers/xdma/user_defined_interrupts_README.md

@@ -34,7 +34,7 @@ The driver needs to be installed once, regardless of how many FPGA slots are ava
 
 The next example shows how an application can register to two events (aka user-defined interrupts) on slot 0
 
-```
+```C
   fd4=open(“/dev/xdma0_events_4”, O_RDONLY);
   fd6=open(“/dev/xdma0_events_6”, O_RDONLY);