congestion : pseudo code tcp congestion typo
mcq-congestion: s/client/sender/ s/server/receiver

It's maybe more clear for everyone to use `sender`/`receiver` instead of `client`/`sender`.
mcq-congestion: fixed typo in the 2nd question

(due to a wrong correction in my previous commit, sorry)
Add missing word "ack"
mcp-ipv6: Q1 & Q2: fixed typo

According to the RFC, it seems the textual representation of an IPv6 address cannot contain more than 7 individual fields if we two semi columns ``::``.

+ Fixed typo to have only one error when the answer is negative

Credits to David
mcp-ipv6: Q3: fixed typo in the addresses of R1

`::A` in the question but `::1` in the FW tables
mcp-ipv6: Q4/6: fixed typo in the addresses of R1

`::A` in the question but `::1` in the FW tables
mcp-ipv6: D1/2: fixed typo in the addresses of R1

`::A` in the question but `::1` in the FW tables

It's just to keep the same logic and the same addresses saw in the previous MCQ
Fix router address in Design Q3
Merge pull request #70 from 363734/patch-2

congestion : pseudo code tcp congestion typo
Merge pull request #104 from matttbe/patch-2

mcq-congestion: s/client/sender/ s/server/receiver
Merge pull request #106 from matttbe/patch-1

mcq-congestion: fixed typo in the 2nd question
Merge pull request #105 from blegat/master

Fix typo
Merge pull request #107 from blegat/mcq-congestion

Add missing word "ack"
Merge pull request #108 from matttbe/patch-3

mcp-ipv6: Q1 & Q2: fixed typo
Merge pull request #109 from matttbe/patch-5

mcp-ipv6: Q3: fixed typo in the addresses of R1
Merge pull request #110 from matttbe/patch-6

mcp-ipv6: Q4/6: fixed typo in the addresses of R1
Merge pull request #111 from matttbe/patch-7

mcp-ipv6: D1/2: fixed typo in the addresses of R1
Merge pull request #112 from target0/patch-1

Fix router address in Design Q3
New version of the IPv6 exercises