Added hw7 submission details.

Author: janfrancu

docs/src/lecture_04/hw.md

@@ -1,4 +1,4 @@
-# Homework 4: More Unit Tests
+# [Homework 4: More Unit Tests](@id hw4)
 
 
 In this homework you will finish writing your unit tests for your `Ecosystem.jl`.

docs/src/lecture_07/hw.md

@@ -1,5 +1,13 @@
 # [Homework 7: Creating world in 3 days/steps](@id hw07)
 
+## How to submit
+Put all the code of inside `hw.jl`. Zip only this file (not its parent folder) and upload it to BRUTE. You should assume that only
+```julia
+using Ecosystem
+using Ecosystem.EcosystemCore
+```
+will be put before your file is executed, but do not include them in your solution. The version of `Ecosystem` pkg and consequently `EcosystemCore` should be the same as in [HW4](@ref hw4).
+
 ```@raw html
 <div class="admonition is-category-homework">
 <header class="admonition-header">Homework (2 points)</header>
@@ -17,7 +25,7 @@ end
 `@add` should not be treated as a macro, but rather just as a syntax, that can be easily matched.
 
 As this is not a small task let's break it into 3 steps
-1. Define method `default_config(::Type{T})` for each `T` in `Grass, Wolf,...`, which returns a tuple of default parameters for that particular agent.
+1. Define method `default_config(::Type{T})` for each `T` in `Grass, Wolf,...`, which returns a named tuple of default parameters for that particular agent (you can choose the default values however you like).
 2. Define method `_add_agents(max_id, count::Int, species::Type{<:Species})` and `_add_agents(max_id, count::Int, species::Type{<:AnimalSpecies}, sex::Type{<:Sex})` that return an array of `count` agents of species `species` with `id` going from `max_id+1` to `max_id+count`. Default parameters should be constructed with `default_config`.
 3. Define the underlying function `_ecosystem(ex)`, which parses the block expression and creates a piece of code that constructs the world.