fix: broken Clarity language reference urls

Fixes blockstack/docs#903

src/pages/smart-contracts/counter-tutorial.md

@@ -165,7 +165,7 @@ Let's get familiar with the tests to understand what the new smart contract shou
 
    First, the [`begin`](/references/language-functions#begin) statement evaluates multiple expressions and returns the value of the last one. In this case, it is used to set a new value and return the new value.
 
-   Next, a [`var-set`](/references/language-functions#var-set) is used to set a new value for the `counter` variable. The new value is constructed using the [`+`](/references/language-functions#-add) (add) statement. This statement takes a number of integers and returns the result. Along with add, Clarity provides statements to subtract, multiply, and divide integers. Find more details in the [Clarity language reference](/references/language-clarity).
+   Next, a [`var-set`](/references/language-functions#var-set) is used to set a new value for the `counter` variable. The new value is constructed using the [`+`](/references/language-functions#-add) (add) statement. This statement takes a number of integers and returns the result. Along with add, Clarity provides statements to subtract, multiply, and divide integers. Find more details in the [Clarity language reference](/references/language-functions).
 
 5. Next, implement a new public function `decrement` to subtract `1` from the `counter` variable. You should have all knowledge needed to succeed at this!
 

src/pages/smart-contracts/overview.md

@@ -66,4 +66,4 @@ then learn how to construct [a counter](/smart-contracts/counter-tutorial), and
 [test your smart contracts](/smart-contracts/testing-contracts) using Mocha.
 
 Once you've got the hang of the general workflow, environment, and language syntax, you should be ready to start writing
-contracts, referring to the [Clarity language reference](/references/language-clarity) as you go.
+contracts, referring to the [Clarity language reference](/references/language-overview) as you go.

src/pages/stacks-blockchain/transactions.md

@@ -391,7 +391,7 @@ The API will respond with a `HTTP 200 - OK` if the transactions was successfully
 There is no explicit time constraint between the construction of a valid signed transaction and when it can be broadcasted. There are, however, some constraint to be aware of. The following reasons can deem a transaction invalid after some period:
 
 - Token transfer: Nonce changed in-between construction and broadcast
-- Contract call or deploy: Block height is evaluated (with [`at-block`](/references/clarity-language#at-block)) and changed in-between construction and broadcast
+- Contract call or deploy: Block height is evaluated (with [`at-block`](/references/language-functions#at-block)) and changed in-between construction and broadcast
 
 ## Querying