[show][interface][counters] Add proposal and changes for fec-histogram

for show int counters fec-histogram subcommand

Signed-off-by: Vaibhav Dahiya <vdahiya@microsoft.com>

doc/Command-Reference.md

@@ -4806,6 +4806,7 @@ Optional argument "-p" specify a period (in seconds) with which to gather counte
  show interfaces counters errors
  show interfaces counters rates
  show interfaces counters rif [-p|--period <period>] [-i <interface_name>]
+ show interfaces counters fec-histogram [-i <interface_name>]
  ```
 
 - Example:
@@ -4923,6 +4924,41 @@ Optionally, you can specify a period (in seconds) with which to gather counters
  admin@sonic:~$ sonic-clear rifcounters
  ```
 
+The "fec-histogram" subcommand is used to display the fec histogram for the port.
+
+When data is transmitted, it's broken down into units called codewords. FEC algorithms add extra data to each codeword that can be used to detect and correct errors in transmission.
+In a FEC histogram, "bins" represent ranges of errors or specific categories of errors. For instance, Bin0 might represent codewords with no errors, while Bin1 could represent codewords with a single bit error, and so on. The histogram shows how many codewords fell into each bin. A high number in the higher bins might indicate a problem with the transmission link, such as signal degradation.
+
+- Example:
+ ```
+ admin@str-s6000-acs-11:/usr/bin$ show interface counters fec-histogram -i <PORT>
+
+ Symbol Errors Per Codeword Codewords
+ -------------------------- ---------
+ BIN_FEC_CODEWORD_S0 4075208478588
+ BIN_FEC_CODEWORD_S1 7
+ BIN_FEC_CODEWORD_S2 0
+ BIN_FEC_CODEWORD_S3 0
+ BIN_FEC_CODEWORD_S4 0
+ BIN_FEC_CODEWORD_S5 0
+ BIN_FEC_CODEWORD_S6 0
+ BIN_FEC_CODEWORD_S7 0
+ BIN_FEC_CODEWORD_S8 0
+ BIN_FEC_CODEWORD_S9 0
+ BIN_FEC_CODEWORD_S10 0
+ BIN_FEC_CODEWORD_S11 0
+ BIN_FEC_CODEWORD_S12 0
+ BIN_FEC_CODEWORD_S13 0
+ BIN_FEC_CODEWORD_S14 0
+ BIN_FEC_CODEWORD_S15 0
+ BIN_FEC_CODEWORD_S16 0
+
+
+ ```
+
+
+
+
 **show interfaces description**
 
 This command displays the key fields of the interfaces such as Operational Status, Administrative Status, Alias and Description.